The objectives of this study were to investigate the seasonal and spatial variations of heavy metal pollution in the overlying water and surface sediments of the Tiaozi River, a tributary of the Liao River, which is one of the seven major rivers and one of the most heavily-polluted rivers in China. Water and sediment samples were collected over four seasons, analyzed for heavy metals (Pb, Cu, Ni, Mn, Cd, and Zn), and assessed with an integrated water quality index (WQI) and a geoaccumulation index (I_geo). Results indicated that the maximum concentrations of all the metals in water and sediments occurred in winter and the minimum in summer. Assessment of the pollution indicated that the water was uncontaminated by heavy metals, but the sediments were slightly contaminated with Cu, Ni, Cd, and Zn. Therefore, the pollution of Cu, Ni, Cd, and Zn in the Tiaozi River Basin should be taken into account during the formation of regional management strategies for the water environment.