In the present study, microbiological and physicochemical qualities of drinking water obtained from the city of Bitlis and its provinces Adilcevaz, Ahlat, Guroymak, Hizan and Tatvan) were studied. A total of 164 water samples, collected from tank and tap waters in spring and autumn, were used as material. Aerobic plate counts were carried out by pour plate technique. While membrane filtration method was used for the counts of enterococcus, co iform, E. coli and sulphite reducing anaerobic bacteria and standard methods were recruited for physicochemical analysis. The results of physicochemical analysis of water samples were found to be in conformity with the standard regulations. Microbiological results of water, however, did not comply with required standards since the findings showed 30% enterococci, 12% coliform, 24% sulphite reducing anaerobic and 8% E. coli. The mean values of pH, Na and Mg, and presence of bacteria except E. coli were higher in autumn than spring. Effect of residential areas on aerobic plate count, coliform and E. coli were found to be insignificant (p>0.05), the effects on all other variables were found to be significant (p<0.05).