The hydraulic performance of drip-irrigation emitters is very important for the design of drip-irrigation systems, especially when commonly available high-head emitters are used in low-head drip-irrigation systems. This study tested three representative commercially available emitters using a custom-made constant-head setup to assess the hydraulic performance in working heads ranging from 0.2 to 10 m. The coefficient of manufacturing variation (Cv) and the emitter discharge exponent (x) were calculated. All the tested emitters were found suitable for low-head drip irrigation systems, but there was a clear effect on the coefficient of manufacturing variation and the emitter discharge exponent of the tested emitters at working heads of less than 1.0 m.