Abstract: The effect of crude leaf extract of Azadirachta indica, Ocimum gratissimum and benlate solution on growth of pathogenic fungi isolated from Cucumeropsis mannii (Melon) seed was studied. Appropriate means of applying the leaf extract to preserve the melon seed was also investigated. The leaf extracts and benlate solution reduced the growth of the fungi with increase in concentration and were effective in preserving melon seeds against fungi for six months. Ocimum gratissimum leaf extract reduced fungal growth more than that of Azadirachta indica. The benlate solution reduced the fungal growth rate most, completely stopping growth at 1.0 and 0.7% concentrations. Melon seeds treated with powdered leaves had no infection when infected with fungi as against seeds treated with ethanol leaf extracts of the medicinal plants which had 16.4% infection when inoculated with Absidia blakelseeana, while the control had 100% infection for each of the fungus. There was a significant reduction of germination when seeds were treated with ethanol leaf extracts. However, seeds treated with powdered leaves of the plants favoured 100% germinations.