A field experiment was conducted to study the effect of two drip irrigation systems (surface and subsurface drip irrigation) and different levels of applied irrigation water (60%, 80%, 100% of ET) on the efficiency of three nematicides [Vaydate (oxamyl); Bio-zeid (Trichoderma album) and Nemaless (Serratia marcescens)] in eliminating parasitic nematodes infected tomato plants. The observed results demonstrated that the subsurface drip irrigation system at water level 80 % of ET led to an increase in the efficiency of nematicides in eliminating parasitic nematodes. There are significant differences between the effect of applicable nematicides in eliminating parasitic nematodes. Vydate gives the best result on the highest death rate with superiority in its efficiency against plant-parasitic nematodes (87.9%) followed by Bio-zeid (81.2%) and Nemaless (71.2%), descending. The activity of parasitic nematodes on tomato plants increases with the increase of applied water in the soil. Where, the lowest average of the numbers of parasitic nematodes juvenile occurred at the lowest applied water level (60 % of ET), reaching (3007.4) with the appliance of a surface drip irrigation system, and the highest average (3697.3) was observed at a higher applied water level (100 % of ET) under the subsurface drip irrigation system. Vaydate led to a decrement in whole mature females of root-knot nematodes, egg masses, and root gall index in percentages (-93.9, -91.5, and -80.0%), followed by Bio-zeid with proportions (-81.2, -75.6, and -60.0%), respectively, under a subsurface drip irrigation system and a water application level of 80% of ET. The reported data of fruit yield confirmed in general that, there were significantly affected by the applied amount of water and different nematicides. The obtained results showed that the IWUE increased by increasing the applied amount of water and there were significant differences in the applied amount of water. Where the higher values of IWUE were recorded under the water application levels of 100% of ET.