Muskmelon (Cucumis melo L.) is a primary crop of Mexico. Nevertheless, the fruit has a high susceptibility to postharvest fungal diseases. Fusarium species are one of the main causes of diseases that limit production of muskmelon. The objective of this study was to characterize and identify by taxonomic keys and molecular markers species of Fusarium related to rot of muskmelon var. Reticulatus in Northwest Mexico. To identify the causative agent, fruits were collectedm from cultivated fields. The isolated fungi were inoculated on muskmelon to determine its pathogenicity. Morphological analyses as well as molecular techniques confirmed that the pathogen was the fungus Fusarium proliferatum.