Studies on the delusion of jealousy are scanty, especially in the elderly population. This study is a retrospective case note study investigating the prevalence of delusions of jealousy in an elderly psychiatric population in Hong Kong. A total of 349 patients were surveyed and five had delusions of jealousy. This gives an overall prevalence of 1.4%, which shows that delusions of jealousy in the elderly are more common than one would expect. There is a predominance among female patients, and the most common psychiatric diagnosis of these patients is delusional disorder.