Temperature inversion is one of the most important meteorological phenomena, in which atmospheric lapse rate is inverted i.e. temperature increases with height instead of decreasing. Inversion plays a significant role in disturbing Air Quality of an area where it exists.Karachiis a coastal city, where sea breeze plays an important role to maintain atmospheric temperature. In this paper, an attempt has been made to find out the temperature inversion layer overKarachiduring 2000 to 2009 and its impact on air quality. The analysis of inversion on monthly basis has been done using JRA 4-time daily temperature data, which has shown the inversion in winter as well as summer seasons with maximum frequency of inversion in monsoon period (July-September), overKarachi. Greater frequency of night time inversion has also found. The Radio-sonde one year daily data of temperature and wind speed ofKarachiis correlated with daily data of haze, mist, dust in-suspension (DIS), visibility and relative humidity to see its impact on air quality. It is observed that the greater frequency of inversion layers at 0000 UTC and 1800 UTC mostly occur in summer months. One of the dominant features is seen in the lower troposphere temperature inversion mostly at 950-850 hPa pressure level.