Objective: This study was conducted to determine the prevalence of gastrointestinal helminths and diagnose the species of important zoonotic helminths in sheep dogs. Methods: Firstly, fecal samples were macroscopically examined; subsequently, formalin-ethyl acetate sedimentation and ZnSO 4 centrifugal floatation techniques were applied for the examination of helminth eggs. PCR technique was utilized to determine the species of E. granu- losus and T. canis in dogs found positive for Taenia spp. and Toxocara spp. Results: Helminth infection was detected in 35.26% of sheep dogs. Taenia spp. was the most common helminth (12.05%), followed by Toxo- cara spp. (9.38%), Toxascaris leonina (6.25%), and Trichuris spp. (4.2%). The positive results in the E. granulosus and T. canis-specific PCR- based molecular tests were obtained in 14 of the Taenia egg-positive samples and in 5 of the Toxocara egg-positive samples from dogs. This study has suggested that coprophagy and feed raw offal and meat to dogs may be responsible for finding atypical helminth eggs in fecal samples from dogs in the absence of an actual infection. Conclusion: To make the diagnosis of their owned parasites of dogs, E. granulosus and T. canis which have zoonotic importance, feces must be examined by both conventional and copro-PCR techniques. In addition to dogs’ feeding habits, other related factors must be taken into account in the epidemiology of helminth infection; thus, precaution and control measures will be more reliable.