OBJECTIVE--To evaluate clinical features and diagnostic investigations in patients with recurrent or unresponsive balanitis in order to institute rational management. DESIGN--Forty-three patients presenting to a genitourinary medicine clinic with recurrent or persistent balanitis were studied. All patients were asked whether they had a history of atopic illness and about their practice of genital washing. All patients were investigated by taking a swab specimen from the preputial area for bacterial and viral culture and 30 underwent biopsy of the affected skin. Follow-up was between three and six months. SETTING--Outpatient genitourinary medicine clinic, St Mary's Hospital, London, UK. RESULTS--In 31 (72%) of the patients a diagnosis of irritant dermatitis was made. In comparison with the remaining patients, they had a greater lifetime incidence of atopic illness and more frequent daily genital washing with soap. For 28 (90%) of these patients, use of emollient creams and restriction of soap washing alone controlled symptoms satisfactorily. For the remaining 12 patients, a variety of diagnoses were made. Biopsy proved a well tolerated and diagnostic investigation, but the isolation of microbial pathogens from preputial swabs was irrelevant to management. CONCLUSION--A history of atopic illness and of the practice of penile washing are important aspects in the evaluation of patients with recurrent balanitis. Biopsy is an important investigation in the condition when it does not seem to be caused by irritant dermatitis.