Abstract: The present study was carried out to evaluate some of the leafy vegetable plants sold in local markets for human consumption to check whether they harbor different parasites stages. A total of 470 leafy vegetable samples were collected from 12 different plant species randomly from local markets in the Riyadh city during the period April and March 2008. The samples were analysed in the laboratory for parasitic stages contained in these samples after washing them in physiological saline and then examining the sediment. Results of the present study has shown that 76 out of 470 samples (16.2%) contained parasite stages. Depending on the type of leafy plant, examined the prevalence of parasitic stages in these plants, was found to be 27.8% (17/61) in lettuce, 22.8% (13/57) in watercress, 20.6% (7/34) in leek, 19.1% (9/47) in green onion, 17.4% (15/87) in parsley, 15.4% (4/26) in spinach, 13.6% (3/22) in basil, 11.5% (3/26) in coriander, 9.4% (3/32) in radish, 5.3% (1/19) in dill and 4.7% (2/42) in mint. No parasites were detected in 17 samples collected from cabbage. Stages of intestinal parasites detected were Entamoeba coli (35.5%), Giardia lamblia (31.6%), Dicrocoelium sp. (28.9%), Ascaris sp. (26.3%), Taenia sp. (19.7%), Blastocystis hominis (17.1%), Fasciola sp. (14.5%), Hymenolepis sp. (14.5%), Ancylostoma sp. (11.8%), Toxoplasma gondii (6.6%) and Trichostrongylus sp. (2.6%). The results indicated a significant seasonal variation (p<0.05), with highest prevalence in spring (23.1%), followed in descending order by Summer (17.9%), Autumn (10.6%) and Winter (9.9%).