The research on parasitoids of the horse chestnut leafminer (Cameraria ohridella Deschka & Dymić, 1986) of the order Hymenoptera was conducted in the years 2004– 2006 in six locations in central Poland. The complex of parasitoids was composed of 14 species. Minotetrastrichus frontalis (Nees) and Pnigalio agraules (Walker), (Hymenoptera: Eulophidae) were the dominant species in all locations. It was noted that sun-exposure of the horse chestnut (Aesculus hippocastanum L.) had a significant effect on abundance of parasitoids attacking the horse chestnut leafminer and their percentage share over the study period. The greatest number of parasitoids was found in the trees which were most exposed to sunray penetration, thus the warmest.