Pumpkin (Cucurbita pepo: Cucurbitaceae) is a heat-labile plant, having nutritional value containing large number of active compounds like carotenoids, alkaloids and flavonoids and necessary for food security against disease causing agents like bacteria, fungi etc. Black rot is a serious disease in pumpkin caused by fungus (Didymella bryoniae) and damaged fruit with the symptoms of dark brown lesions but causal organism identification through DNA is still unknown. We collected infected leaf from C. pepp from the vicinity of The University of Agriculture, Faisalabad and isolated D. bryoniae on the respective media. Then morphologically identification was observed through fungal growth pattern, growth color, spores shape, spores color, hyphal septation. For the confirmation of Koch's postulates, the pathogenicity test was performed. CTAB method and Internal Transcribed Spacer region were applied to isolate and amplify the fungal genomic DNA respectively, by using universal primers ITS1/ITS4. The analysis of polygenetic of an amplified product revealed that black rot caused by D. bryoniae in pumpkin.