Pumpkin cultivation ( Cucurbita pepo L.) is relevant because it is one of the most important vegetables due to its consumption worldwide. However, a limitation for its production is the incidence of diseases, among which is the powdery mildew, causing losses of 50 % to 100 % in yield. Literature identifies two genera causing this disease worldwide: Golovinomyces cichoracearum (DC.) V.P. Heluta and Podosphaera xanthii (Castagne) U. Braun &Shishkoff. Both genera were identified in different crops in Sinaloa, Mexico, but the causal agent of powdery mildew in pumpkin in Tehuacan has not been identified. Therefore, the objective of this research was to corroborate the presence of this pathogen in Tehuacan. The morphological and molecular identification was carried out considering the anamorph and telomorph states. The morphological analysis was made by means of optical microscopy and the molecular analysis by means of PCR. The ITS region of the ribosomal DNA (ITS1 5.8 S and ITS2) was amplified and its sequence was compared with the records of the Genbank NCBI. Powdery mildew showed simple conidiophores, mainly ovoid conidia with fibrosin bodies inside. The sexual phase showed spherical casmotecia with septated mycelial appendages, with an ovoid asca with an eye opening of 18.5 µm in diameter and eight ascospores inside. These characteristics and the sequences obtained coincided with those described for Podosphaera xanthii , which allowed the identification of this pathogen as the causal agent of powdery mildew in pumpkin in Tehuacan, Puebla.