ROPAGATION of cucurbits via grafted seedlings exhibits an increasing trend in vegetable cultivation in Egypt. This is due to the limited cultivated area, intensive cultivation, and increasing stress leading to problems that negatively affect production. While the investigations for determining the accurate fertilization amount of the grafted plants are still scarce. Therefore, this experiment was conducted in a private farm located in Badr city, El-Behera governorate, Egypt, to evaluate the performance of non-grafted (control) and grafted cantaloupe plants (Cucumis melo var. cantaloupenses, cv. Marella F1 hybrid) onto four rootstock cultivars (Cobalt, Ferro, Star, and 6001) then fertilized with nitrogen (N), phosphorus (P), and potassium (K) at rates of 60, 80, 100, 120, and 140% of these nutrients recommendations for cantaloupe fertilization during the two successive growing seasons of 2018 and 2019. The results indicated that grafting cantaloupe plants onto the tested rootstocks had promoted a higher vegetative growth manifested as plant length, leaves number, shoot fresh and dry weight, stem diameter, and root dry weight, as well as raising leaves content of nitrogen, phosphorus, potassium, and the greenness index (chlorophyll readings, SPAD) along with boosting the average fruit weight, and early and total yield than the control when all were fertilized by any of the applied fertilization rates. Worthy, rootstocks of Cobalt and Ferro provided the greatest superiority in all investigated growth and fruit yield characteristics of the cantaloupe plant through fertilizing by the 140% NPK fertilization rate.