Background Food allergy and seafood (fish, mollusk, and crustacean) consumption have increased considerably over the past 40 years. Seafood allergy is now a leading cause of anaphylaxis in both the United States and Australia. However, there is only limited published data describing the clinical presentation and management of seafood allergy. Objectives To describe the characteristics of a large cohort of children with seafood allergy. Methods Using a retrospective chart review, we collected data on all children presenting to our Tertiary Allergy Service with an allergic reaction to seafood between 2006 and 2009. Results 167 children had a history of definite clinical reaction to seafood and/or positive food challenge (103 male, 62%). 94% had evidence of co-existent atopic disease. Prawn/shrimp was the most common seafood implicated. One-fifth presented with a history of anaphylaxis to seafood. Over 50% of crustacean-allergic children could tolerate non-crustacean fish. Sensitization to other fish species was very common in fish-allergic children, with one third reporting clinical reactions to at least two species; 16% developed symptoms to fish vapours. In children with allergy to tuna and/or salmon, at least 21% were able to tolerate the fish in a tinned form. Conclusions Seafood is a relatively common and important cause of food allergy in Australian children, presenting with a high rate of anaphylaxis.