Grafting is a technique by which two or more plants are joined, forming a single plant. One of the main purposes of grafting in vegetable crops is to induce resistance to pests and diseases. The effects of rootstock were transmitted through vascular bundle to the scion, causing qualitative and quantitative traits in scion. Liriomyza sativae (Dip.: Agromyzidae) and Traialeurodes vaporariorum (Hem.: Aleyrodidae) are economic pests on vegetables such as greenhouse cucumber (cucumis sativus). Chemical control of the pests has always been difficult. So other control methods must be considered. The experiment was conducted in a randomized complete block design with 4 treatments and 4 replications in the research greenhouse of Isfahan Center (Isfahan, Iran). Treatments were two cultivars of greenhouse cucumber (Yalda and Spadana), non-grafted and grafted on an interspecies hybrid of pumpkin (named as Cobalt). Sampling was carried out on two middle plants in each plot. For evaluating leafminer, infestation percentage (infested leaves/ plant) was determined. However, due to differences in the number and extent of larval mines in the infected leaves, damage rating (based on a 10-degree scale) and cumulative numbers of mines were recorded using a stratified random sampling on six leaves of the selected plants. Population density of whitefly was sampled through leaf-turn method and rapid counting on the underside of six leaves of the selected plants, using a stratified random sampling. Two treatment groups, non-grafted versus grafted, were compared using orthogonal contrast. Results for leafminer showed that significant differences among treatments for all three variables. For infestation percentage, treatments were placed in two groups. Non-grafted treatments of Yalda and Spadana (28.24 and 23.41 %, respectively) in a group and grafted that treatments (9.48 and 10.24 %, respectively) in a separate group. For cumulative number of mines, grafted Yalda, with the lowest mean (0.98 mines/ leaf) had significant difference with other treatments. For damage rating, treatments were placed in four groups. Non-grafted Yalda had the highest mean (1.27) and grafted treatments of Yalda and Spadana had the lowest mean (both 1.00). There was no significant difference among treatments for population density of whitefly, while the highest means were belonged to non-grafted treatments of Yalda and Spadana (17.08 and 12.33 number/ leaf, respectively), and the lowest means were belonged to grafted that treatments (10.37 and 9.14 number/ leaf, respectively). Orthogonal contrast showed significant differences between two treatment groups, non-grafted versus grafted. Overall, the damage of vegetable leafminer and greenhouse whitefly were lower on greenhouse cucumber grafted on the rootstock of pumpkin hybrid.