The observation of an oversized egg of the American Crocodile Crocodylus acutus in exhibition at Ejido La Manzanilla crocodile farm museum, located in La Manzanilla del Mar village on the southern coast of Jalisco, Mexico, was recorded. The oversized egg is from a wild nest laid on 12 April 2013, on the sandy bar at the mouth of the La Manzanilla estuary adjacent to the museum. The egg weighed 500 g, with a length of 22.50 cm (measured linearly), and width ranged from 5.70 cm to 6.0 cm. The etiology of the oversized egg is unknown; however, it may be due to a low level of calcium in the diet ration of the breeding female.