Reptiles have proven to have a versatile and efficient nonspecific immune system adapted to the environments in which they commonly live. Phospholipase A₂ (PLA₂) is important hydrolytic enzyme involved in the regulation of specific types of messengers, with significant roles in the innate immune response. A number of agents that exert effects on cellular receptors emit a series of signals leading to the increased activity of PLA₂. Phospholipase A₂ has been identified and characterized in temperature, plasma concentration, and kinetic dependence in two species of caiman. The results of these studies suggest that the high PLA₂ activities observed in caiman plasma may be an important component of a well-developed innate immunity. Based on the knowledge of their properties, this powerful immunologic component should be evaluated as a possible application in the veterinary or even human therapeutic industry. Additionally, this is another reason to consider these animals excellent models for the study of immune phylogenetic mechanisms.