Irrigation performance assessment is of high priority in irrigation research priorities needed to solve the problem of irrigation development & management. Practically many irrigation systems are performing below their capacities. This may lead to non-uniform and unreliable water distribution. Therefore, a good starting point is to assess the performance of available irrigation systems in order to identify areas of lapses in the system design and make amends. A field study was undertaken to evaluate the performance of on-line non pressure compensating of 2, 4 and 8 lph discharge ratings. The system was tested for its uniformity coefficient, emission uniformity, manufacturing coefficient of variation and head-discharge relationship.