The seagull (Larus dominicanus) commonly can be observed near human fishing activities, as this species feeds on discards from fishing. This common interaction between a seabird and human fishing activity (both commercial and recreational), provides an easy source of food, but is not without risk for the birds. We report here clinical, radiographic and anatomopathological findings of an esophageal perforation caused by fishing gear in a specimen of Larus dominicanus found alive on a beach in the state of São Paulo which illustrated a harmful effect of stemming from recreational fishing. Clinical examination revealed a nylon thread in the oral cavity with the presence of caseous suggestive of ingestion of lost fishing gear, paralysis of the pelvic limbs and a decrease in the pain reflex associated with sternal decubitus, suggestive of food intoxication. Necroscopic examination revealed two hooks, one in the caudal portion of the esophagus with esophageal and pulmonary perforation, and the other in the muscular stomach. These injuries would have been expected to lead to the death of the bird. These anatomopathological findings confirmed the seriousness of the injuries. This reinforces the importance of studies focused on the interaction of recreational fishing artifacts (hooks, lines) with coastal birds on the Brazilian coast, in order to develop a preventative strategy.