Field and laboratory studies were oriented to evaluate the relative resistance of three cantaloupe cultivars; Tenorio RZ, 62, and Ideal to some sap sucking pest; whitefly, Bemisia tabaci (Genn), onion thrips, Thrips tabaci L, aphid, Aphis gossypii (Glover) and two spotted spider mite Tetranychus urticae Koch. The results showed that the total number of pests were the highest on Tenorio RZ cultivar and the least on Ideal during two seasons. Ideal cultivar had the highest levels of alkaloids and phenolics compound, while terpene compounds was undetectable. Also, the results showed that Tenorio RZ cultivar was having the lowest least levels of secondary metabolites. During summer, numbers of sucking pests were the least on Ideal. Results showed also that the levels of plant secondary metabolites tend to decrease pest population levels.