This epidemiological study was conducted in different regions of Costa Rica to determine the prevalence of the developmental stages of potential zoonotic intestinal helminths of dogs and cats in public places. Samples were collected within three main climate zones including rural and urban areas during both the rainy and the dry season. Faecal and environmental samples were taken from 69 parks and beaches. Of the faecal samples 3% contained Toxascaris spp. eggs, 7% Toxocara spp. eggs and 55% contained ancylostomidae eggs. Of the soil samples, 2% contained ancylostomidae eggs and 0.8% contained ascarid eggs. Significant differences in the presence of parasites were found in faecal samples of dry, moist and wet climate zones and between the dry and rainy seasons. Significant differences in the presence of eggs and larvae were also found in the grass samples in the dry, the moist and the wet climate zones and between the different seasons. No significant differences were found between rural and urban areas.