The lionfish (Pterois volitans) has established in the Colombian Caribbean coast. Its presence was reported for the first time in continental Colombia in 2009, but its abundance has increased significantly by the end of 2009 and 2010, being now common to find it in the entire Colombian Caribbean. The present study evaluates the diet components of the lionfish in Santa Marta and Tayrona National Park. Five teleost families (Apogonidae, Gobiidae, Serranidae, Clupeidae, and Pomacentridae) and some crustaceans were identified as components of the diet of the lionfish. Some of these organisms belong to families of ecological and economic importance, which can have impacts on populations of local fish as has happened in other latitudes. Consequently, this species should be controlled and managed in the area to avoid further loss of diversity and abundance of ecological and commercially important fish species in Colombia.