Inadequate urban storm water drainage problems represent one of the most common sources of complaint from the citizens in many cities of Bangladesh and this problem is getting worse and worse with the ongoing high rate of urbanization. Drainage congestion has already been treated as a major urban environmental problem for Chattogram as well as in Bangladesh. It has become a major issue in the port city Chattogram in recent year. A few hours’ monsoon rain makes the overflow of water from the drains of Chattogram city. Rather it creates vulnerability and play a significant impact on the urban environment, economic environment, ecology, human habitat and so on. This study investigates the impacts of drainage congestion on the urban environment in Chattogram city, Bangladesh. Primary data have been collected through 200 questionnaires administered to residents of the study area, and 4 FGDs have been conducted to validate and cross-check the data obtained from the questionnaires. The secondary data have been collected from various sources like books, journals, magazines, CDA, CCC, CWASA reports, etc. The results of this study show that the dominant causes of urban drainage congestion are: lack of drainage, population growth, encroachment into natural drainage, excessive rainfall, unplanned urbanization, blockages of drains by solid waste, absence of dredging system, etc. This drainage congestion is a problem creating adverse social, physical, economic, and environmental impacts on the life and living in Chittagong. Disruption of transport and communication systems; drainage death trap, damage to infrastructure; destruction of vegetation and aquatic habitats; and loss of income potentials are the effects of drainage congestion on city life. The aggregate outcome of this research suggests that Chittagong will face rigorous environmental problems if this trend of urban drainage congestion continues. The aggregate outcome of this research suggests that solid waste management, regular dredging, raising awareness of the residents and close coordination among urban authorities and collaboration between public and private sectors are needed for sustainable operation of the drainage system to minimize urban drainage congestion in Chittagong.