The present study deals with the assessment of physico-chemical characteristics of Dokan, Derbendikhan and Duhok lakes. The physico-chemical characteristics of these lakes have been studied and analyzed for a year, during January-April-July and October 2009. Seasonal variations of two sampling sites of the lakes have been observed. Various parameters including air temperature, water temperature, electrical conductivity, TDS, pH, total alkalinity, total hardness, dissolved oxygen, calcium, magnesium, sodium, potassium, sulfate, chloride, nitrite and phosphate have been analyzed. The study has revealed that there are significant seasonal variations in some physico-chemical parameters and as a whole most of the parameters are different in the three lakes.