Helminths are among the most-commonly encountered disease-causing agents in dogs all over the world, including Vietnam. A cross-sectional survey was carried out between March and December 2019 in four dog slaughter-slabs in Yen Lap District, Phu Tho Province, northern Vietnam, aiming to reveal the occurrence of gastrointestinal helminths in dogs. Worms were collected from 350 dog samples and identified by morphological techniques followed by molecular methods for tapeworms and hookworms. Nine species, including Taenia hydatigena, Spirometra erinaceieuropaei, Dipylidium caninum, Spirocerca lupi, Ancylostoma ceylanicum, Ancylostoma caninum, Toxocara canis, Toxascaris leonina and Trichuris vulpis, were found to occur in this area. Infection with at least one worm species was found in 272 dogs (77.7%; 95% Wilson score CI: 73.1–81.8%). The most common species was A. ceylanicum, with a prevalence of 45.1% (95% Wilson score CI: 40.0–50.4%) while T. hydatigena had a very low prevalence of 0.3% (95% Exact CI: 0.0–1.6%). Co-infection with hookworms and D. caninum was common. Five of the recovered helminth species have a zoonotic potential. Control of these parasites is necessary in order to protect human and animal health