Global organic agriculture and consumption of organic food has continuously increased over the past decades. The aim of the research was to determine and compare cadmium (Cd) and lead (Pb) concentrations in organic and conventional root and tuber vegetables from the Serbian market. Samples of three root and tuber vegetables commonly consumed in Serbia, including potatoes, carrots and beetroots, were collected at two green markets and four supermarkets in the territory of the city of Belgrade, Serbia. Concentrations of Cd and Pb in fresh weight were determined byatomic absorption spectroscopy(AAS). Mean concentrations of Cd and Pb in two types of vegetables were compared by the t-test. Cd and Pb concentrations in both types of vegetables were below allowable limits. Potato mean Cd concentration was significantly lower in the organic than in the conventional type (0.021 mg kg^-1 and 0.037 mg kg^-1, respectively). In carrots, it was the opposite, Cd concentration was higher in the organic type, but the difference was not significant either between the two types or for beetroots. Results indicated lower Pb levels in organic potatoes and beetroots, and higher Pb levels in organic carrots, but differences between means were not significant in all tested vegetables. Obtained results are not conclusive, but they indicate lower or similar concentrations of both metals in organic vegetables in comparison to conventional types.