This study investigated the water quality of some of the ex-mining lakes in Perak State of Malaysia for possible use as alternative to water supply and compared them to water quality of some of the rivers used for intake of water treatment. A total of twelve (12) water samples were collected for analyses from selected sampling sites. These samples were analyzed for physico-chemical properties, heavy metals concentrations, and organic pollutants concentrations. The analyzed results indicated that average temperature varied from 28.1 °C to 34.1 °C, pH 6.2 to 9.0, EC 55 to 400 μs/cm, turbidity 5.6 to 74.2 NTU, DO 3.21 to 9.56 mg/l, TDS 36.8 to 268 mg/l, F- 0.017 to 0.182 mg/l, Cl- 0.483 to 3.339 mg/l, Br- 0 to 0.392 mg/l, SO4 2- 0.051 to 15.307 mg/l, Mg 0.833 to 1.466 mg/l, Na 0.669 to 3.668 mg/l, and Ca 2.85 to 26.77 mg/l. Heavy metals concentrations (mg/l) were: Zn 0.04 to 0.057, Pb 0.019 to 0.075, Cd not detected, Ni 0.013 to 0.105, As not detected to 0.004, and Cu not detected while COD 4 to 51 mg/l. Analyses revealed that all the water samples were turbid and containing slightly high concentration of Pb. Generally, they had common water quality problem. Further work should carry out more tests on other water quality parameters particularly on heavy metals, chemical and biological pollutants at different seasons. © (2014) Trans Tech Publications, Switzerland.