The study was conducted to assess the determinants for rural water project sustainability in Rufiji district, Tanzania. A household questionnaire to 180 respondents in six villages was used in data collection. This was supplemented by discussions with ordinary water users and water attendants. Descriptive statistical methods such as percentages and cross tabulations were used as qualitative analytical techniques. Quantitative methods included Pearson Chi square and Logistic regression model. The collected data were analysed using SPSS software. In order to determine the main factors for rural water project sustainability the Logistic regression model was applied and the results show that cox and snell (R2) was 0.470 and Nagelkerke (R2) was 0.670, this indicates that the model was fit to explain the change in the dependent variable as a result of change in the independent variable. From the results it show that only two independent variable which are number of maintenance done and number of spare parts replaced were found significant at p ≤ 0.000 and p ≤ 0.004, respectively. The findings implies that the positive signs attached to the estimated coefficients of such variables indicate that the greater the values of these variables the higher the tendency to maintain sustainability of rural water supply. The negative signs of price of water and time for collecting water, indicate that the greater the value of the variable the lower the probability to maintain sustainability of rural water projects. The study concludes that functionality of rural water project depends on multiple factors such as maintenance, availability of spareparts, community participation, and short distances from the sources, reasonable water prices and good management of water funds.The Embassy of Belgium; Belgium Technical Cooperation (BTC)