To give an overview of the literature on balanitis, with a special emphasis on infective causes. A data search was performed using the OVID CD plus Medline 1967-1995, using balanitis and balanoposthitis as textword search strategy. Specific subjects such as anaerobic infection, Zoon's balanitis were sought separately and subgroups combined. Original articles and abstracts were referenced to illustrate each condition. These were mainly English language articles, but included appropriate non-English language papers. Balanitis is a common condition among genitourinary medicine clinic attendees, the cause often remaining undiagnosed. Many cases are caused by infection, with candida being the most frequently diagnosed. However, gardnerella and anaerobic infections are common, and there are a wide variety of other rarer infective causes. In addition irritant balanitis is probably a contributing factor in many cases. Balanitis which persists and in which the cause remains unclear warrants biopsy.