Objective  To describe variations in genital dimensions of normal women.

Design  Observational cross-sectional study.

Setting  Elizabeth Garrett Anderson Hospital, University College Hospital NHS Trust, London, UK.

Population  Fifty premenopausal women having gynaecological procedures not involving the external genitalia under general anaesthetic.

Methods  A cross sectional study using digital photography and measurements of the external genitalia.

Main outcome measures  Clitoral size, labial length and width, colour and rugosity, vaginal length, distance from clitoris to urethral orifice, distance from posterior fourchette to anterior anal margin.

Results  A wide range of values were noted for each measurement. There was no statistically significant association with age, parity, ethnicity, hormonal use or history of sexual activity.

Conclusion  Women vary widely in genital dimensions. This information should be made available to women when considering surgical procedures on the genitals, decisions for which must be carefully considered between surgeon and woman.