Sparganosis is a parasitic disease caused by tapeworms of the genus Spirometra and is widely distributed in East and Southeast Asia, including the Republic of Korea. During a field survey conducted on 21 June 2022 at Jangdo Island, Sinan-gun, Jeollanam-do, Republic of Korea, a Gloydius ussuriensis was collected, and a single parasite was found inside the right hemipenis. The worm measured 1.93 cm in total length and was identified as belonging to the genus Spirometra based on morphological features such as a white, wrinkled body and the presence of a head with a sucker. A single parasitized viper had a body condition index (BCI) of 1.52, which was lower than the national average (1.60 ± 0.01). Although Spirometra tapeworms are typically found in the subcutaneous tissues or coelomic cavities of snakes, this study represents the first case of a Spirometra parasite inhabiting the epidermis of the hemipenis.