Tomato (Lycopersicon esculentum) fruits obtained from the local market in Sango Ota, Ogun State, Nigeria, were inoculated with Aspergillus niger from cultures grown in the laboratory and incubated under appropriate conditions of temperature and moisture to initiate infection for seven days. Extensive lesions and subsequent collapse of the tomato fruits inoculated with A. niger occurred within a week of incubation. The uninoculated fruits retained the bright red colour and remained firm throughout the seven days. The pH and the probable implication of the results obtained from this research work can be very useful in utilizing tomato fruits in tomato processing companies in Nigeria
