The degradation of cocoa beans by thermophilic fungi isolated from fermenting cocoa and the factors affecting their activities were studied. The fungi were Mucor pusillus Lindt., Aspergillus fumigatus Fres. and Thermoascus aurantiacus Miehe sensu Apinis. A high occurrence of these fungi on the fermenting cocoa beans was recorded at 45° C and at 50° C. Growth-temperature determinations showed Aspergillus fumigatus to be thermotolerant while the others are thermophilic. The ecological factors operating within the fermenting mass of cocoa beans were found to be particularly suitable for colonization by thermophilous microbes. All the fungi caused considerable changes in the oil and free fatty acid contents of the blended cocoa beans when grown on them at 40° C. Their best degradative activities were recorded at a narrow pH range of 6.5–7.0 and a temperature range of 37°–45° C. All the fungi were found to be lipolytic due to their ability to hydrolyse natural fats and synthetic triglycerides. Because of the zoopathogenic nature of these fungi and other microbes associated with fermenting cocoa beans, cautious handling of this product during and after processing is suggested.