Zucchini yellow mosaic virus (ZYMV) infection causes heavy losses in cucurbit crops grown in the Mediterranean, Central Europe, the United States, and Mexico. Recently, ZYMV was found affecting muskmelon (Cucumis melo L.) in Colima, Mexico. An experiment was carried out under dry tropical conditions with the objectives: 1) to determine the effect of ZYMV on flowering and yield of muskmelon cv. Primo, and 2) to evaluate its transmission by some aphid species. Perfect and staminate flowers were significantly reduced when ZYMV was inoculated during vegetative growth, flowering, and fruit set. ZYMV affected yield when it was inoculated from vegetative growth to flowering and fruit set. In plants inoculated during vegetative growth the yield was null, while those inoculated at early flowering and fruit set the yield was reduced by 80% and 49%, respectively. The yield was not affected when ZYMV was inoculated on fruit growth. The aphid Myzus persicae, Aphis gossypii, A. spiraecola, and Uroleucon ambrosia-transmited ZYMV from Cucurbita pepo to Cucumis melo; but Aphis nert, did not.