Abstract: This study was carried out to determine the effects of different fertigation practices on irrigation system performance in in-line emitters using Samandag region well water. The experiment was conducted at the research field of the Samandag Vocational College, University of Mustafa Kemal, Hatay, from 2001 to 2002. In the experiment, three different emitters (1.7, .75 and 4.0 L h-1), three different fertilizer treatments (no-fertilizer, MKP+Ca(NO3)2+KNO3+KSO4+NH4NO3 and NH4NO3+KSO4+MKP) combinations with flushing and no flushing management groups were tested in three replications. Emitter discharge rates were tested at the beginning and end of every season to determine emitter flow variations. The effect of the different fertilizer treatments on system performances was found to be statistically significant. Fertilizers which included both calcium and sulfates resulted in lower system performance than the others. Emitters that have the lowest flow rates had the lowest performance. The acid treatment and flushing management increased the system performance slightly, but it was found not to be statistically significant.