Alpacas (Vicugna pacos), native to South America, were recently introduced to Korea, primarily for tourism-related activities. However, information on their parasitic infections in alpacas within the region are limited. This study aimed to investigate the longitudinal prevalence and diversity of gastrointestinal parasites in an alpaca herd on a single farm in Korea and to assess the potential risks for reinfection and interspecies transmission. Between June 2022 and June 2023 (excluding December 2022 and January 2023), fecal samples were collected monthly from a herd of 61 alpacas housed on a farm on Jeju Island, Korea. Coprological examination of 406 samples was performed using a modified McMaster technique, and parasites were identified morphologically. Six gastrointestinal parasite taxa were identified: strongyles, Trichuris sp., capillarids, Moniezia sp., Eimeria lamae, and Eimeria macusaniensis. The overall gastrointestinal parasite prevalence was 11.3%, with strongyles and Trichuris sp. most frequently identified. No seasonal trends were observed, and mixed infections were present in five animals. The prevalence was markedly lower compared with reports from Japan, Poland, and Australia, reflecting the restricted pasture access implemented by Korea’s alpaca management systems, which are primarily tourism-oriented. Neither Nematodirus spp. nor zoonotic parasites were detected. This is the first longitudinal investigation of gastrointestinal parasites in alpacas in Korea. Although the overall prevalence was low, environmental contamination and the risk of reinfection are ongoing concerns. These findings highlight the need for routine surveillance, targeted parasite control, and consistent veterinary oversight, particularly as alpaca populations expand in Korea.