In developing countries, huge quantities of wastewater are disposed into water bodies without any treatment. Process complexity, high energy consumption, and high capital and operational costs have made the conventional treatment methods difficult to adopt in these countries. Lack of trained and skilled personnel to operate these highly sophisticated and complex systems is also a key problem associated with the conventional treatment methods. Constructed wetlands (CW) are engineered systems that have been designed and constructed to utilize the natural processes involving wetland vegetation, soils and the associated microbial assemblages to assist in treating wastewaters. It is a low cost and energy efficient option for a country like Pakistan which faces increased power shortages-an essential requirement for the majority of treatment methods. Therefore, its application for the treatment of wastewater of Lahore city was investigated in this study. A local plant, Reed (Phragmites) was evaluated for its potential use in constructed wetland. A lab scale wetland (using an earth pot) was used with reed as vegetation. Removal efficiency of the system was evaluated at different detention times ranging from 1-5 days. The results demonstrated 90% removal for TSS, 75% removal for BOD and 80% removal for COD at 5 days detention time. The mean effluent concentration of 10 mg/L, 40 mg/L and 68 mg/L for TSS, BOD and COD, respectively was obtained at 5-days detention period, thus complying with effluent standards of Pakistan. The results of the study support the suitability of CW for Lahore and also motivate for detailed pilot plant studies.