This research work was carried out to control post-harvest cassava (Manihot esculenta Crantz) spoilage fungi using extracts of three herbs namely Andrographis paniculata, Spondias mombin and Chromolaena odorata. Fungi were isolated from diseased harvested cassava tubers, characterized and identified phenotypically and tested for pathogenicity on healthy harvested cassava tubers. The pathogenic fungal isolates were screened for their susceptibility to water and ethanolic extracts of the selected plant species. Results showed the presence of seven fungal species including yeast, Aspergillus niger, Penicullium notatum, Fusarium oxysparium, Mucor sp., Rhizopus sp. and Botryodiplodia theobromae. A. niger was the most prevalence with 100% occurrence while the other recorded as 88.8% (yeasts), 55.6% (Rhizopus and P. notatum), 44.4% (F. oxysporum), 33.3% (Mucor sp.) and 22.2% (B. theobromae). Four of the seven fungal species viz.  Aspergillus, Penicillum, Fusarium and Botryodiplodia showed pathogenicity to varying extents, and were subjected to antifungal activity tests using the extracts. The extracts caused varying levels of radial growth inhibition of the different test organisms. The water extracts caused 38–46% (C. odorata extract), 36– 45% (S. mombin) and 50–58% (A. paniculata) inhibition of the pathogens while their respective ethanol extracts inhibited the organisms by 63–75%, 66–76% and 69–88% in comparison to 89–97% recorded for mancozeb, a commercial fungicide. The inhibition of the pathogen isolates varied significantly with Botryodiplodia being the least inhibited (38–69%) while Penicillum was the most inhibited fungus (36–88%). Inhibition of Aspergillus and Fusarium species was recorded as 41–83% and 38–84%, respectively. The ethanolic extracts were found to be more potent than the water extracts while the extracts of A. paniculata was the most potent and that of C. odorata was the least effective.