Dogs have close contact with humans, which represents a serious potential source of direct transmission of parasites to man. Gastrointestinal parasites are a major impediment to dog health worldwide through direct and indirect losses. Most dogs are sub-clinically infected and continuously shed infective helminth eggs in their faeces, contaminating the environment and increasing health risks to man. In developing countries like Nigeria, the risks of zoonotic infection from dogs are high, owing to the lack of prevalence studies to determine their existence in the environment. The aim of this research is to determine the prevalence and extent of gastrointestinal parasites in healthy dogs, survey the types of gastrointestinal infestation in dogs kept by owners in the study area, determine the effect of sex, types and location of dogs in the prevalence of gastrointestinal parasites and prevalence of gastrointestinal parasite in Ondo city. A total number of 122 samples were examined. 30 were positive with 15 protozoan species, namely: Ancylostoma caninum, Capillaria boehmi, coccidia, oocyst, cyistoisospora canis, Dipylidium caninum, Toxocara canis, Trichuris vulpis, Toxascaris leonina, Paragonimus kellicotti, Physaloptera sp, Uncinaria sp, Sarcocystis spp, Taeniasp, Spirocerci lupi and Eimeria sp with Capillaria sp having the highest prevalence and Paragominus sp (3.3%) with the least prevalence. Out of the four sample sites, Ajue had the highest prevalence with (35%), Laje (28%), Ondo Town (20%) and Bagbe with the least prevalence of (20%). From the breeds examined, the local breeds had the highest prevalence of gastrointestinal parasites (40.8%), cross-breeds (15.2%) and exotic breeds had the least prevalence (12.5%). Based on their age group, puppies less than 1 year had a high prevalence of infection at (25%), while the adult had a prevalence rate of (23.8%). In relation to the sex of the dogs, the prevalence rate was higher in males (25%) than in females (24%). This study indicates possible means of zoonotic infections if dogs are not properly cared for or treated, especially young puppies who have been around for less than one year.