While Tanzania is endowed with enormous natural water resources, access to clean and safe water remains a great challenge. For instance, out of twenty urban water supply authorities, only three (Arusha, Songea and Tanga) supply water continuously. This paper examines factors influencing organisation efficiency of water supply utilities in Tanzania, using Mbeya Urban Water Supply Authority (UWSA) as case in point. The unit of analysis of this study were all employees of the Mbeya UWSA. Data were collected through structured questionnaires, key informant interviews and documentary analysis. Descriptive analysis and onesample t-test were employed as data analysis methods. The findings show that human resource competences in waste water management, civil engineering, distribution of water resources, other industrial services and agricultural water management contributes to a small extent to organisation efficiency of the utility. Shortage of funds, lack of priorities in government budget and low rate of return on investment contributes less to organisation efficiency of the utility. The use of information and communication technology moderately contributes to organisation efficiency while availability of working facilities, engagement in survey and innovation in water management contributes to a small extent to organisation efficiency of the utility. The study recommends Mbeya UWSA to take deliberate efforts to improve the attributes of human resource competences, financial resources and physical resources that have bearing effect on the organization efficiency of the utility in delivering services to customers.