The persistence of the pesticides, prothiofos (Tokuthion SO% EC), dimethoate (perfekthion 40% EC) and diniconazole (sumi-eigth 5% EC), on and in grape leaves was studied. Grape leaves are commonly used in Egypt in human consumption. Grape vines, var. King Robby, were sprayed with the recommended rate of each pesticide on June 10, 1996. The estimated half-life values (111_50) of the applied pesticides were 17, 23, 27 hours for prothiofos, dimethoate and diniconazole, re‌spectively. Data revealed that dimethoate was the most degradable pesti‌cide compared to the other two pesticides. Its residues on and in grape leaves decreased to a level below its Codex MRL ten days after spraying with total loss of 98.6%. Prothiofos was the most persistent pesticide in this study. Its residues level on and in grape leaves was significantly high (26.67 ppm) ten days after application and should not be used or mar‌keted for human consumption. Although diniconazole showed low levels of residues on and in grape leaves, ten days was not enough to reduce its residues in the leaves to its MRL level. The pre-harvest interval (PHI) should not be less than three weeks. The results also indicated that boiling process was very effective in eliminating dimethoate residues on and in treated grape leaves. The reduction of its residues due to this process was about 98%. The boiled grape leaves can be marketed one day after dimethoate treatment. On the contrary, boiling of treated grape leaves was less effective in reduc‌ing prothiofos or diniconazole residues.The reduction in their residues af‌ter this process were 35% for prothiofos and 30-50% for diniconazole.