The current methods of diagnosis for non-specific genital infection (NSGI) in clinics in England and Wales are described. In most clinics (92%) microscopical findings were used by consultants to establish the diagnosis of non-specific urethritis (NSU) in male patients. However, the microscopical criteria that they used in reaching a diagnosis varied between clinics. The most commonly applied criterion was that of less than five leucocytes per high power field. NSGI in female patients and non-specific proctitis in passive homosexuals were recognised as distincy in 60% of clinics and the latter in 57%. Among those who recognised these conditions the diagnostic criteria varied. The establishment of acceptable and uniform criteria for diagnosis are discussed.