Adults of Coccinella septempunctata L. (Coleoptera: Coccinellidae) were collected from under leaf litter located in overwintering areas. After killing in alcohol, they were dissected and observed for presence of mermithids in the body cavity of adults. Parasitism of C. septempunctata by Hexamermis sp. was recorded 13.3% and 13.8% in females and males, respectively. Overall, 87.5% of the eight C. septempunctata contained one nematode and 12.5% contained two nematodes. The mean body length of post parasitic stages (n = 7) was 34.2 ± 8.82 (23.4 – 42.2) mm. It is seen that Hexamermis sp. has a significant negative effect on natural populations of this predator in overwintering areas during the year of the study.