The aim of the studies was to determine significance of parasitoids as biocontrol agents against teafrollers in apple orchards. The studies were performed in different parts of Poland in 1994–2001. An average parasitization level of caterpillars amounted to ca. 8.6%, and it varied broadly up to individual orchards (from 2.4 to 32.4%). A natural parasitization level was strictly related to the intensity of orchards’ protection against pests. Higher parasitization was observed in case of less protected orchards, and in those ones with a great number of leafrollers. The greatest share in parasitizing leafroller caterpillars was stated for hymenopterans belonging to two families: Ichneumonidae and Braconidae. Populations of leafrollers were most effectively reduced by the following parasitoid species: Ascogaster rufidens, Apanteles ater, Meteorus ictericus, Macrocentrus linearis and M. thoracicus of Braconidae as well as Campoplex mutabilis, Lissonota segmentator, Phytodietus segmentator, Itoplectis maculator, Diadegma armillatum and Apechthis rufata of Ichneumonidae. The results of conducted research also revealed preferences of particular parasitoids to parasitize some leafroller species. A. rufidens had the greatest share in parasitizing caterpillars of Pandemis heparana. Among hymenopterani parasitoids of Archips rosanus, the one most numerously occurring was C. mutabilis, also considered as the main parasitoid of Acleris rhombana. In parasitizing the leafroller Adoxophyes orana the greatest share fell to M. ictericus while in case of Spilonota ocellana – the most frequent parasitoid was A. quadridentata. Tachinid flies were found to be of a minor importance in parasitization of leafroller caterpillars. They were only raised from four leafroller species, and their largest share fell in parasitization of A. rosanus. Parasitation of A. rosanus eggs by Trichogramma sp. varied broadly depending on individual orchards and growing seasons, and ranged 0.8 to 33.9%.