We conducted a study of the prevalence and clinical characteristics of aquagenic pruritus (AP) in 996 employees at a general hospital. Forty-five of them claimed that they had AP, thus giving a reported prevalence of 4.5%; 12 were excluded for various reasons and a detailed workup was carried out in 33 people. In more than 75% of the cases AP had started before age 30 and lasted for over 10 years in 42%. The onset of AP occurred within 5 min of exposure in 76% of the cases and usually lasted between 10 and 30 min. In most cases no association could be demonstrated between AP and each of the following factors: place, season, time of day, water temperature, type of soap, towelling or mental stress. AP in at least one other family member was found in 33% of the cases.