The aim of this study was to determine the physico-chemical and microbiological quality of drinking water regions of southern Algeria For this purpose, 16 samples 15 water samples from the cities of El Oued, Ouargla, Ghardaia and Adrar were taken either at the consumer's tap, or from well water. Our results show that the physical and chemical quality of the waters of Southern Algeria is poor and rich in mineral salts: the conductivity is between a minimum of 1374μs/cm and and a maximum of 4070μs/cm while the European standards recommend values between 180 and 1000μs/cm. The hardness is very high. It ranges between 42° F and 134° F. According to international and national standards, all waters have excessive fluoride levels. Moreover, Analyzed waters present an organic pollution represented by the concentration of the organic matter which is lower than the Algerian and European standards (5mg / l O2 dissolved). Finally, analysis of physical parameters and indicators of mineralization, alkalinity, salinity and hardness, groundwater sampled showed a great diversity in nature that is a function of the water which they belong, that due to rock or agricultural and industrial activities in the region.