Abstract: The present study has been undertaken to establish the spatial and seasonal variation patterns in the surface water quality of the Jia- Bharali river basin, Assam, India with respect to the concentrations of dissolved trace metals (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn). The monitoring was done during wet and dry seasons for a period of 3 years from three types of sources – ponds, rivers and streams on both banks of the Jia - Bharali River. The surface water has As content (0.10 – 6.18 µg/L). 20.1 % of the samples in the rainy season and 34.4 % in the dry season show Cd content higher then the desirable limit of 0.005 mg/L. 54.4 % of the surface water samples also have Pb above the permissible limit of 0.05 mg/L during the rainy season while in the dry season, 85.8% surface water sources show Pb above the limit. Similarly, 60.1 % water samples during the wet season and 80.1 % water samples during the dry season show Ni content above the permissible limit of 0.02 mg/L. Zn content of the surface water sources are however very low throughout the year. The results are correlated to the dominant geological features, local environmental setting, and differences in water utilization by the people, variations in runoff volume, etc.