This study was conducted to collect discharge rates at 4 different pressure levels of 50, 100, 150 and 200 kPa to assess the hydraulic performances of various kinds of emitters (including Mono-tandem, Hydrogol, In line-168, Matic, Katif 4 and Katif 8), calculate the coefficient of manufacturing variation, emitter discharge coefficient and emitter discharge exponent, to establish the emitter's flow rate sensitivity to pressure and comparing the results to the manufactures' specifications. Results indicated that design should be based on reliable test data, not on manufacturer's supplied data. Mono-tandem, In-line 168 and Hydrogol, were classified as NPC and Matic, Katif 4 and Katif were classified as PC as expected. Except Matic, discharge of emitters was uniformly distributed at all operating pressures.