Environmental isotopic study has been con-ducted in Faridkot and Muktsar districts of Punjab to assess the uranium contamination as well as to determine the isotopic signatures of contaminated groundwater. Results indicate that U levels range from 3 to 190μg/L and ten samples are contaminated out of twenty collected. Uranium contamination is observed both in shallow and deep groundwaters but decreases with depth. Positive correlation was found between alkalinity and U. The δ¹⁸ O values range between-9 and-6% and do not show any dis-tinction between contaminated and uncontaminated groundwater.