Abstract. Dhaka, with an extremely high resident’s growth rate, is one of the most densely populated megacity in the world. An evident increment in the air quality index has been a concern for the city for the last couple of decades while most recently, it has topped the index of the world’s cities with the worst AQI for several consecutive days. With the continual growth of the number of multi-stored buildings to support its population, the city opened up a step towards an urban sustainability - an opportunity to exploit the rooftops. The aim of the study is to explore the potential of the rooftop gardening utilizing the significant amount of effective surface area it can already provide. Result show the health concerns of the citizens are directly associated with the alarming concentration of the pollutant, especially particulate matter (PM2.5, PM10), CO2, SO2, and NOx. Data from various relevant sources have been used to compute the pollutant absorption rate (mg/m2) by average sizable gardening plants each day. One of the most significant findings from this study is that a planned rooftop gardening in this metropolitan area confirms the increased absorption of CO2 and PM10 to an extent of 63.25% and 66.67% respectively in 30 years. Beside the air quality benefit, this article also includes some practical environmental benefits of rooftop gardening from an urban perspective.