Six female patients with a mean age of 40 years presenting with a suburethral diverticulum were treated between August 1990 and October 1992. The commonest functional symptoms were recurrent urinary tract infections (2/3 of cases) and post-voiding urethral discharge (1/2 of cases). Clinical examination revealed a tender anterior vaginal mass in only one half of cases. Only retrograde and voiding cystourethrography and transvaginal ultrasonography always demonstrated a direct or indirect image of the diverticulum. The suburethral diverticulum was resected via a transvaginal approach in the ventral supine position after sterilisation of the urine by prolonged antibiotic therapy. Urine drainage was generally ensured by a suprapubic catheter allowing antegrade cystography on the 15th day, prior to clamping then removal of the catheter. All but one of the patients immediately regained satisfactory micturition without dysuria or stress incontinence. Restoration of micturition was delayed in one patient with feelings of incomplete bladder emptying, but she urinated normally at three months. Postoperative imaging (retrograde and voiding cystourethrography, transvaginal ultrasonography) demonstrated resolution of the diverticulum in 5 cases. One patient had persistent signs of a small, residual diverticulum on antegrade cystography on the 15th day. Suburethral diverticulum is a rare disease of middle-aged women for which transvaginal surgical excision in the ventral supine position gives very good results.