Objective To estimate the prevalence of bacterial vaginosis in women referred to a gynaecology clinic, and to compare two methods of diagnosing bacterial vaginosis.

Setting Gynaecology Clinic at Northwick Park Hospital

Subjects 114 women aged 16 to 65 referred consecutively to the gynaecology clinic of one consultant.

Main outcome measures Detection of bacterial vaginosis by standard compound criteria and by examination of a Gram stained smear of fluid from the posterior vaginal fornix.

Results Bacterial vaginosis was detected by both the Gram stain and the compound criteria in 13 women. There was no correlation between the symptom of vaginal discharge and the diagnosis of bacterial vaginosis in this population, but the presence of discharge noted by the clinician was associated with bacterial vaginosis.

Conclusions The prevalence of bacterial vaginosis was 11%. The Gram stain provides a simple and inexpensive method for laboratory confirmation of bacterial vaginosis where facilities for using the compound criteria are not available.