The phytochemical screening and evaluation of efficacy of ethanolic extract of wild Dioscorea dumetorum was determined using standard microbiological and physiochemical methods against some plant pathogens. The extraction of bioactive constituents of the samples was conducted using 80% aqueous ethanolic solution. The phytochemical screening revealed the presence of Alkaloids 8.6%, Saponins 10.8%, Tannins 3.7%, flavonoids 2.5%, steroids 1.7%. The antifungal potentials of the crude extract was tested against fungi isolates of Rhizopus nodosus, Fusarium solani, Aspergillus flavus, Rhizopus stolonifer, Synchytrium endobiotium, phytophthora infestans, Spongospora subterranea, Venturia inaequalis, Magnaporthe oryzae, Ustilago maydis, Fusarium oxysporum, Fusarium moniliforme, Sclerotium rolfsii, Penicillium digitatum, Pencillium italium. The minimum inhibitory concentration (MIC) ranged between 10-35 mg/ml. The antifungal activity against ustilago maydis was the highest with zone of inhibition of 35.4mm, Spongospora substerranea 30.5mm, Synchyfrium endobiotium 28.2mm, Rhizopus nodosus 25.1mm, Rhizopus stolonifer 24.3mm, Aspergillus flavus 24.0mm, Fusorium solani 23.5mm, Sclerotium rolfsii 18.6mm, Fusarium oxysporum 16.8mm, Penicillium digitatum 14.3mm, Pencillium italium 13.7mm, Venturia inaequalis 11.2mm, phytophthora infestans 10.3mm. These results show antifungal action and medicinal potentials of aqueous ethanolic crude extract of Dioscorea dumetorum. This research is at the preliminary stage and it is ongoing. It may proceed to the isolation and characterization of the most bioactive component(s) of this wild yam. This research is therefore open to agricultural research plant pathologist, pharmacologist, food and nutrition, food safety, security and quality control, food and chemical toxicology and food and drug analysis. This research aim at strategies of controlling post harvest losses caused by fungi during storage. The research is educative because this wild yam is grown in most region of the world. The research is a practical solution to the problem of fungi infestation in wide range of crops. The local people of Igede tribe of Nigeria has used the aqueous extract of this wild yam species for years to control post harvest losses without understanding the scientific implications.