Aim: A cross-sectional study was carried out from November 2011 to April 2012 to determine the prevalence and species of gastrointestinal (GI) helminth parasites in pet and stray dogs as a potential risk for human health in Bahir Dar town, northwestern Ethiopia. Materials and Methods:A total of 384 and 46 faecal samples were collected from pet and stray dogs, respectively and examined by using standard coprologic techniques. Results:The overall prevalence of GI helminth infection in pet and stray dogs was 75.26 and 84.78%, respectively. The detected parasites with their frequencies in pet dogs were Ancylostoma caninum (78.89%), Toxocara canis (39.79%), Dipylidium caninum (29.75%), Strongyloides stercoralis (29.06%), Taeniidae (23.87%) and Trichuris vulpis (7.95%). Stray dogs were found more likely to be polyparasitized and presented higher prevalence of A. caninum, T. canis, S. stercoralis, Trichuris vulpis and Taeniidae (P < 0.05) than domiciled ones. Diphyllobothrium latum was detected only in 10.25% of stray dogs. Toxocara canis and A. caninum (P < 0.05) were detected more frequently in dogs with less than 6 months of age (P < 0.05) than old age dogs. The sex or breed groups didn't significantly affect the prevalence of parasites. A significant variation was recorded (P < 0.05) between different feeding systems where higher prevalence was observed in uncontrolled feeding group (82.18%) compared to controlled feeding (32.08%). Conclusion:Different gastrointestinal parasites in pet and stray dogs were identified in the study area that can potentially infect humans and cause serious public-health problems. Thus, concerted efforts should therefore be made to educate dog owners to embrace modern dog disease control programs and measures have to be taken on stray dogs.