An outdoor experiment was carried out at EL-Gemmeiza Agricultural Research Station, Gharbia Province, during August and September, 2018. The hydraulic performance of four types of rotating plastic impact sprinklers (S1, S2, S3 and S4) under four operating pressures (P1=100 kPa, P2=125 kPa, P3=150 kPa and P4=175 kPa) and two overlapping patterns (50 % D=50 % throw diameter and 65 % D=65 % throw diameter) were evaluated. The results referred to that: increasing operating pressure increased discharge rate and radius of throw for different sprinklers; the sprinklers arranged according to discharge rate as S2> S3> S1> S4. Maximum discharge rate of 1965 l/h was recorded for sprinkler S2 at 175 kPa operating pressure. The greatest radius of throw was 12 m obtained by sprinkler S2 at 175 kPa operating pressure.The sprinklers arranged according to application rate as S2> S3> S1> S4. The highest gross and net precipitation rates were 5.81 and 4.53 mm h^-1 obtained by sprinkler S1 at 125 and 175 kPa operating pressure respectively. The highest application efficiency of 91.82 % was achieved by sprinkler S2 at 100 kPa operating pressure. The highest Christensen uniformity coefficient (CU) of 92.2 % was obtained by sprinkler S2 at 100 kPa operating pressure and 50 % D. The highest distribution uniformity (DU) of 88.3 % was obtained by sprinkler S3 at 175 kPa operating pressure and 50 % D.