Performance evaluation of irrigation system is essential to assess how far the goals and objectives set out at the time of project formulation of the system have been achieved. Efficient operation and management for small-scale irrigation system plays an important role in the sustainability of irrigated agriculture. This study was intended to evaluate the performance of Timbel mehal small-scale irrigation scheme using efficiency indicators, maintenance indicators organizational set up indicators and assess the water delivery, farmer’s perception. Primary data through field measurement, household survey, key informant interviews and group discussion, and Secondary data from different reports, standards in FAO, and Legal office data were taken. The result of this study showed that the conveyance and application efficiencies of the scheme were fund to be as 68.67% and 56.28% respectively, which led to an overall scheme efficiency of 36.8%. RWS and RIS of the scheme were 1.47 and 1.53, respectively. Sustainable irrigation indictor of irrigation scheme was found to be 1.3, meaning the current area under irrigation was increased by 9.33% of initially irrigated command area. The results on the effectiveness of infrastructures show that 33.33% of initially installed structures were non-functional. Based on the assessment of farmer’s perception about the performance of the irrigation scheme, the respondents believe that major conflict that make the scheme to be payment of water tax, rotational water, water theft or deviation of water in canal and water shortage in downstream cause of high water lose in traditional canal. In general, based on the different researchers, the evaluation and assessment indicated a low performance of the Timbel irrigation scheme and non-uniform water distribution among upstream and downstream water users, where by high water lose in the downstream of the earthen canal. In this causes for great water scarcit y and conflict in this irrigation scheme. Generally, to concluded that to enhance efficiency of irrigation and water management it is highly important to pay special attention in unlined canal change in to lined and by sharing water use management experience from different irrigation scheme which the scheme has good performance. Keywords: Performance evaluation, Efficiency, indicators, Timbel mehal irrigation scheme.