The present study has been undertaken to evaluate the performance of wastewater treatment systems (WWTS) in three different districts (Kolkata, Howra and Hugli) in West Bengal, India. Performance of these wastewater treatment plants are essential parameter to be monitored as the treated effluent is discharged into River Ganga which is the National River of India. The performance evaluation will also help for the better understanding of design and operating difficulties in wastewater treatment plants.