Dissertation (MSc Natural Resources Management)This study has investigated the water quality and incidence of water related diseases in Dodoma and Iringa regions. Water quality assessment was carried on several villages in Kongwa, Iringa and Mufindi districts during dry season in early March to mid April, 2020. Methods used were sampling and testing physical chemical and biological characteristics of water as well as carrying out in-depth interviews to key informants, observation and documentary review. Microbial characteristics of water samples were determined by Most Probable Number (MPN) method. Findings have shown variation of physical, chemical and biological characteristics of water between different sampling points. As for the physical parameters, some areas were within acceptable limits where others were not. Water pH, Electrical Conductivity and Total Dissolved Solids exceeded the standards required by WHO and TBS for drinking water. The rest parameters fall within the acceptable standards. For the chemical parameters they were found within the required standards for drinking water quality except ammonium and nitrate which were found to exceed WHO and TBS limits in almost all villages. Microbial analysis demonstrated variations. Faecal coliform and presence of E.coli were detected in some water sources and some not. Detection was observed from Chamkoroma, Ugogoni, and Mbande villages in Kongwa District. In addition, findings revealed that diarrhoea, typhoid, eye infections and skin infections, gastro intestinal infections (GIT), urinary tract infections (UTI), giardiasis and dysentery are among of water borne diseases, which affects health of under five children across the study area mostly related to chemical and biological characteristics observed as per correlation analysis results. The study recommends regular testing and monitoring of drinking water quality and awareness creation among the community members on water contamination, its effects and preventive measures through seminars and workshops.