The present work was focused on the bacteriological quality of drinking water originated from wells, drillings and rivers within the oil field of Doba-Chad. In fact, the rural population inhabiting this bassin is not provided with a safe and convenient system of drinking water. Therefore, they get their drinking water from available sources such as wells, drillings and rivers. Staphylococcus aureus, E.coli, fecal Streptococcus and Salmonella strains were evidenced from 10 samples each of these waters sources based on French norms V08-057-1, NF V08-053, NF T 90-416 and ISO 657/A1. The average number of strains detected in 100 ml Were Staphylococcus aureus (697, 2385, 527); E. coli (137, 74, 36), fecal Streptococcus (6275, 4171, 1654), respectively from wells, forages and rivers. The contamination rate of Salmonella in different sources varied from 10% in wells, 20% in rivers, to 30% in drillings. The elevated number of these microorganisms is more than values recommended by OMS directives for the quality of drinking water. Corrective and urgents measures are needed to improve the quality of these water resources rich in pathogens that are the sanitary risks, and the causes of infectious diseases such as gastro-enterite, diorrhea, typhoid, and skin diseases.