The aim of this study which was carried out at Sakha Agricultural Research Station, Kafr el-Shiekh Governorate is to determine the most suitable irrigation frequencies for pea grown under drip irrigation system. The irrigation treatments were based on cumulative pan evaporation (CPE) at different empirical pan factors (0.6, 0.8, 1.0, 1.2, 1.4 and 1.6 of CPE. Irrigation interval was based on available water = Ef * CPE. Results indicated that reducing the irrigation interval through increasing empirical pan factor (Ef) value from 0.6 to 1.6 has a highly significant effect on fresh seed yield. The highest mean fresh seed yield in the two seasons (1066.5 kg/fed.) was obtained when irrigation was done at Ef 1.6 and the lowest fresh seed yield (507.5 kg/fed.) was obtained when we use Ef 0.6.  The highest value of crop water productivity CWP (0.93 kg/m³) was obtained by using Ef 1.6 and the lowest CWP (0.45 kg/m³) was obtained by using Ef 0.6 .  The highest value of biological yield (7.67 ton/fed.) was get with the treatment of Ef 1.4, where the lowest value (5.16 ton/fed.) was resulted from the treatment irrigation at Ef 0.8. Studied treatments have highly significant effects on fresh pod yields. The highest fresh pod yield (2.98 ton/fed.) was produced from treatment irrigation at Ef 1.6, where the lowest value (1.94 ton/fed.) was obtained by using Ef 1.0. Insignificant differences were found between the studied treatment means regarding to weight of 100 seeds and percentage of moisture in seeds. Number of seeds/pod was high significantly influenced by studied treatments. The number of seeds/pod (9.0) resulted from 1.6 as Ef treatment. While, the lowest number of seeds/pod (7.2) was obtained from Ef 0.6 treatment. The highest value of netting percentage 36.1% was obtained from irrigation at Ef 1.2 and 1.6 treatments, while the lowest 21.2% was obtained from irrigation at Ef 0.6 treatment. The highest mean value of pod filling (0.86) was resulted from irrigation at Ef 1.0, 1.2 and 1.6 treatments. On the other hand the lowest value (0.76) of the pod filling was obtained from irrigation at Ef 1.4. So, it is useful to recommend that the proper irrigation interval could be   scheduled according to CPE.