This paper examines the water quality of the Aboabo River in Kumasi, Ghana using the Canadian Council of Ministers of the Environment water quality index (CCME-WQI).Water samples were collected from five sampling stations namely; Pankrono, Moshie Zongo, Aboabo, Asokwa and Atonsu. The model employs both bacteriological and physicochemical parameters namely Escherichia coli (E-Coli), pH, Temperature, Total dissolve solids, Total phosphate, Nitrate, Biological oxygen demand (BOD) and Dissolved oxygen (DO) in the determination of the water quality index of the Aboabo River. Findings of the model classify the Aboabo River as poor with overall water quality index of 17.05. Station indices developed using the model were 19.87, 19.60, 15.67, 14.40, 15.73 for Pankrono, Moshie Zongo, Aboabo, Asokwa and Atonsu respectively. The index at each station classifies the River as poor. The deteriorating nature of the Aboabo River is directly linked to poor sanitary conditions prevalent in the Aboabo Catchment as well as the presence of cottage industries that discharge their effluent into the river.