In mid June, an outbreak of Salmonella Javiana infections was detected involving three children who attended the same elementary school. In the following days other illnesses at the school were detected. Most of the ill students had attended an outdoor picnic or an in-school party. The epidemiologic study implicated watermelon in this outbreak. Leftover watermelon was served at a birthday party and at a home; additional illnesses resulted. A sample of the watermelon grew Salmonella Javiana in the laboratory that was a genetic match to the strain isolated from case-patients. The watermelon had not been washed prior to cutting and was served over a three hour period at room temperature.