Introducing Fish to Babies: Best Choices, Mercury Guide and Safety Tips

Fish is safe for babies from 6 months and is one of the most nutritionally valuable foods you can offer — packed with brain-building DHA, high-quality protein, and essential minerals. Choose low-mercury varieties like salmon, cod, sardines, and canned light tuna and serve 1–2 times per week. Avoid high-mercury fish like shark, swordfish, and king mackerel entirely.

Why Fish Is Excellent for Babies

Fish provides a unique combination of nutrients that are especially important for infant brain and nervous system development:

• DHA (docosahexaenoic acid) — An omega-3 fatty acid that accounts for about 40% of the fat in the brain and 60% of the fat in the retina. DHA is critical for cognitive development and visual acuity in infants.
• High-quality protein — Contains all essential amino acids in easily digestible form
• Vitamin D — Fatty fish like salmon is one of the few natural dietary sources of vitamin D
• Iodine — Essential for thyroid function and brain development
• Selenium — An antioxidant mineral important for immune function
• Vitamin B12 — Critical for nervous system development and red blood cell formation
• Iron and zinc — Especially in fatty fish and shellfish

The AAP, the American Heart Association, and the Dietary Guidelines for Americans all encourage regular fish consumption in infancy and early childhood, choosing low-mercury varieties.

Mercury in Fish: What You Need to Know

Mercury is a naturally occurring heavy metal that accumulates in fish through the food chain. Large predatory fish at the top of the food chain accumulate the highest levels of mercury (called methylmercury). Methylmercury is a neurotoxin that can damage the developing nervous system of infants and young children.

The key is choosing fish with low mercury levels — and the good news is that most popular, commonly available fish are low in mercury.

FDA Fish Categories for Young Children

The FDA and EPA classify fish into three categories for children:

Best Choices (2–3 servings per week)

These are the lowest-mercury fish and the best choices for regular feeding:

• Salmon — High in DHA; wild-caught Pacific salmon is among the best options
• Trout — Freshwater trout is low in mercury and high in omega-3s
• Herring — Excellent source of DHA; strong flavor some babies need time to accept
• Sardines (canned in water) — Extremely nutrient-dense; low mercury; soft, easy to mash
• Cod — Mild white fish; very low mercury; easy to cook and puree
• Tilapia — Very mild flavor; low mercury; widely available and affordable
• Catfish — Mild, low mercury; easy for babies
• Shrimp — Low mercury; ensure fully cooked; always check for shells and tails; fine pieces for babies
• Canned light tuna (skipjack) — Affordable and convenient; low mercury
• Pollock — Mild white fish; used in many fish sticks; low mercury
• Flounder/Sole — Very mild, delicate white fish; low mercury
• Haddock — Similar to cod; mild and low mercury

Good Choices (1 serving per week)

• White (albacore) canned tuna
• Yellowfin tuna
• Mahi-mahi
• Halibut
• Carp
• Grouper

Avoid (High Mercury — Not for Babies)

• Shark
• Swordfish
• King mackerel (note: Atlantic mackerel is fine; it's king mackerel to avoid)
• Tilefish (Gulf of Mexico)
• Orange roughy
• Bigeye tuna (often labeled "ahi tuna" in restaurants)
• Marlin

How to Introduce Fish to Babies

First Introduction: Treat as an Allergen

Fish is one of the top 9 major allergens. When introducing fish for the first time, follow allergen introduction protocols:

1. Choose a time when you'll be home for 2 hours after the introduction — introduce in the morning
2. Don't introduce fish on the same day as any other new food
3. Your baby should be healthy — don't introduce during illness
4. Start with a very small amount (1/4 teaspoon of fish mixed into puree)
5. Wait 10 minutes, then give more if no reaction
6. Watch for 2 hours after the full serving

How to Prepare Fish for Babies

6–8 Months

• Steam, bake, or poach fish until fully cooked and flaky. Never undercook fish for babies.
• Remove all bones meticulously — check by running fingers through the flesh. Even small pin bones can be dangerous.
• Mash or blend with a little breast milk, formula, or vegetable broth to a puree consistency
• Mix into vegetable purees — sweet potato + salmon puree is a popular combination

8–10 Months

• Offer finely flaked cooked fish as finger food
• Soft fish cakes or fishballs (mashed fish mixed with mashed potato, formed into patties)
• Fish stirred into soft-cooked rice or pasta

10–12 Months

• Larger flakes of fish as finger food
• Simple fish tacos with soft tortilla and mashed avocado
• Homemade fish pie with mashed potato topping

The Bone Check: Critical Safety Step

Before serving any fish to a baby, run your fingers carefully through the cooked flesh to feel for bones. Pay special attention to the center "backbone" area and the lateral (side) pin bones. Even "boneless" fish fillets can contain pin bones. Use fish tweezers or needle-nose pliers to remove any bones you find.

Fish Allergy: Signs to Watch For

Fish allergy affects approximately 0.5% of children in the US. Unlike many food allergies, fish allergy is often lifelong. Signs of a fish allergic reaction include:

• Hives or skin rash (especially around the mouth)
• Swelling of lips, face, or eyes
• Vomiting or diarrhea
• Runny nose, sneezing, watery eyes
• In severe cases: difficulty breathing, wheezing, throat tightening (anaphylaxis)

Note: Fish and shellfish are separate allergen categories. A baby allergic to fish (finfish) may or may not also be allergic to shellfish. Consult your allergist for guidance on cross-reactivity.

Serving Size for Babies

• 6–8 months: 1–2 tablespoons of fish puree per meal
• 8–12 months: 2–4 tablespoons (about 1–1.5 oz) per meal
• Frequency: 1–2 times per week for best choices; up to 3 times per week for lowest-mercury varieties like salmon

Frequently Asked Questions

When can babies eat fish?

From 6 months when they begin solid foods. Early introduction of fish, like other allergens, does not increase and may decrease allergy risk.

Which fish are safest for babies?

Salmon, trout, herring, sardines, cod, tilapia, catfish, shrimp, and canned light tuna are all "best choices" with low mercury. Serve 1–2 times per week.

What fish should babies avoid?

Avoid shark, swordfish, king mackerel, tilefish (Gulf of Mexico), orange roughy, bigeye tuna, and marlin — all high in mercury.

Can babies eat canned tuna?

Canned light (skipjack) tuna is a "best choice" — appropriate for babies. White albacore is a "good choice" (1 serving/week). Bigeye tuna (ahi) should be avoided.

Is fish a common allergen for babies?

Yes. Fish is one of the top 9 allergens. Introduce as an allergen — morning introduction, one new food at a time, watch for 2 hours. Fish and shellfish allergies are often lifelong.

Also see our guide on introducing eggs to babies and iron-rich foods for babies.

This article is for informational purposes only and does not constitute medical advice. Always consult your pediatrician. Sources: FDA/EPA Fish Advice, AAP HealthyChildren.org, CDC Infant and Toddler Nutrition.