A study was carried out between 1980 and 1983 to determine the natural enemies associated with eggs, larvae and pupae of Pieris brassicae collected from cultivated crucifers in Valdivia, Chile. No natural enemies were found at the egg stage. However, 82.24% of the larvae were parasitized by Apanteles glomeratus [Cotesia glomerata] and Apanteles sp. Both of these braconids were attacked by hyperparasitoids of the genera Hemicallidioles, Isdromas and Perissocentrus. Various bacteria parasitized 15.63% of the larvae. In the pupal stage, the natural enemies and their average rates of parasitism were. Pteromalus puparum 6.75%, the ichneumonid Coccygomimus fuscipes [Pimpla fuscipes] 23.37% and the fungus Beauveria brongniartii 5.82%. During the period of the study, 0.74% of the immature stages of Pieris brassicae became adults. An independent density relation between natural enemies and immature stages was observed. none