Use of arbuscular mycorrhizal fungi (MA) on horticultural plant production has great potential as a biotechnological alternative; however, information on its effects on the early growth phase of honeydew melon is lacking. Nevertheless, it would seem that inoculation at the time of sowing would decrease the stress of transplant, improve root vigor, make plants grow faster, improve drought resistance, and lessen the effect of roots diseases. In this study, we evaluated the effects of inoculating honeydew melon seedlings with two commercial formulations of MA fungi at different study times in an effort to select for higher resistance and infective capacity. `Moonshine' hybrid melon seeds were sown in trials with 200 cavities containing specific doses of inoculate: 0, 100, 200, 250, 500, and 1000 cc/trial of BuRIZE, Mycorrhiza NES. A factorial design was used (formulations and study times) with a randomized distribution and four replications. Four destructive samples were taken at 10, 15, 20, and 25 days after inoculations. Number of leaves, shoot fresh weight, dry weight, root fresh weight, foliar area, and mycorrhizal colonization were recorded. Results obtained showed a highly significant effect between commercial formulations and study times and an interaction of both factors to studied variables. Mycorrhizal colonization percentages were too low (0.3% to 1.7%). At 20 days after inoculations, it was possible to see all the components of functional arbuscular mycorrhizal symbiosis on melon plants roots. Using commercial formulations of mycorrhizal fungi decreased applications of fertilizers in melon plants.