Tomatoes are particularly vulnerable to microbial spoilage at calyces and wound sites on the fruit surface. Compared to the fruit surface, the calyx carries the major part of the microbial load, consisting of epiphytic bacteria and moulds. Disinfection of tomato fruits, as a means of extending quality shelf life, was studied using trans-cinnamaldehyde, a compound occurring naturally in plants. Treatment of tomatoes with an aqueous solution of 13 mM cinnamaldehyde reduced the number of bacteria and fungi by one order of magnitude within 10 and 30 min, respectively. With tomatoes that had been treated for 30 min with cinnamaldehyde, visible mould growth was delayed by seven days during storage under modified atmosphere conditions at 18°C.