The aim of this study was to identify the causal agent of a postharvest black rot of pumpkin (Cucurbita maxima Duch.), commonly known as “picada negra” in Chile and to evaluate the efficacy of chemical control alternatives. Based on morphological characteristics and temperature response, the causal agent of black rot was identified as Ulocladium cucurbitae (Letendre and Roum.) Simmons. This fungus was consistently obtained through repeated isolations made from disease fruits and it was subsequently reisolated from healthy fruits that were artificially inoculated with isolates of U. cucurbitae. The following fungicides and fungicide mixtures were evaluated to control U. cucurbitae in vitro andin vivo: iprodione, prochloraz-carbendazim, epoxiconazole-kresoxim methyl, iprodione-bromuconazole, folpet, metconazole, chlorothalonil, mancozeb, imazalil and benomyl. Metconazole, imazalil and prochloraz-carbendazim were the most effective fungicides to inhibit mycelial growth of U. cucurbitae in vitro and were selected for further studies. Using these fungicides, an in vivo trial was performed on pumpkin fruit pieces, inoculated with U. cucurbitae before and after fungicide treatments. The mixture of prochloraz+carbendazim (300 g·L-1 + 80 g·L-1, Sportak Alpha SC), at the rate of 0.042 µg·mL-1, provided the best control. Infection was favored by the presence of wounds in the fruits.