Watermelon belongs to the family cucuritaceae, which consist of nearly 100 genera and over 750 species. Watermelon is grown annually and can be up to 3meters long. They are widely distributed in the tropics and sub-tropics, and a few species occurs in temperate regions. The method employed was to isolate and identify the pathogens causing rot from watermelon. The fungi pathogen isolated were A.niger, S.cerevisiae, A.wentii. the fungi were cultured with the moringa leaf and turmeric extracts using Potato Dextrose Agar (PDA) and Mycelia growth and zone inhibition was observed. Moringa oleifera (Moringa leaf) and Curcuma longa (Turmeric) have inhibitory potential on post harvest rot causing fungal diseases of watermelon and suggest its ability to prolonging its shelf-life and prevent diseases. For the result, three fungi were isolated and identified which includes Aspergillus niger, Aspergillus wentii, Sacharomyces cerevisiae. Pathogenicity confirmed that the isolated fungi were the causative agent of the rot. A.niger colonies appear black in PDA plates, which was initially white and later turned black. Under the microscope the mycelia is separate, condiophores are long with vesicle like tips. In conclusion, all the tested fungal isolates were responsible for decay of watermelon fruits. The same isolates contaminate fresh cut ready to eat watermelon fruits, this shows that they used compromised surfaces of their fruits such as wounds to cause rots. More research should be conducted on the pathogencity of these fungi associated with spoilage of the watermelon fruits to confirm the primary pathogens and to differentiate them from secondary invaders. Proper handling methods should be adopted by both farmers and consumers to minimize the fungal deterioration of the watermelon fruit