BackgroundUnderstanding parasite diversity in wild and captive animal populations has critical implications for both individual animal health and ecosystem dynamics in a broader sense. In mountain gazelles (Gazella gazella), the gastrointestinal helminth community is poorly understood, limiting our efforts in the conservation of this endangered bovid species. This species has only two remaining populations in the world, including the isolated northernmost population in Türkiye.ObjectivesTo identify and compare the diversity and prevalence of gastrointestinal helminths in captive and free‐ranging populations of mountain gazelles in Hatay, Türkiye, and to assess potential zoonotic risks.MethodsIn total, 105 fresh faecal samples, 45 individual samples and 60 faecal samples, representing 16 pools, from both captive and free‐ranging populations were collected and analysed using Fulleborn flotation, Benedek sedimentation and Bearman–Wetzel methods faecal flotation methods, including the McMaster technique to determine the severity of infection.ResultsWe detected 12 helminth taxa in our examination of faecal samples, including gastrointestinal nematodes, lungworms and trematodes. Parasites from the Trichostrongyloidea family demonstrated variable hatching stages and rates, potentially influenced by ambient conditions. We also detected one protozoan among the samples. Our results revealed a higher diversity of parasites in free‐ranging populations compared to captive ones.ConclusionsThis study underscores the necessity for regular parasitological surveillance in both captive and free‐ranging wildlife populations for effective conservation management. It also contributes to the ‘One Health’ perspective by highlighting the potential zoonotic risks posed by parasites in wild ruminants. Our results have implications for the conservation and management of the mountain gazelle.