Abstract: To study environmental bacteria, samples were collected from different indoor and out door sites of Chittagong city over one year from Jan 2002 to December 2002.The frequency of over all load in different media was recorded as 25.87, 44.20 and 29.91% in the rainy season, winter and summer, respectively. The prevalence of bacteria found 82.52% and fungal flora 17.48% in out door sites and in case of indoor sites, bacterial flora was 76.93% and fungal flora was found 23.07%. The most frequently isolated organisms Staphylococcus aureus, Bacillus cereus and Bacillus subtilis were found all over the sites and seasons of the year. The percentage of Staphylococcus spp was dominant among all 110 staphylococcus media in tea stall (13.69%) and Kodomtoli (14.37%) in case of indoors and out doors, respectively all the year round.