A case of giant vesical diverticulum is reported. A 31-year-old man was admitted with intermittent self-catheterization for 6 months duration due to urinary retention. A cystogram demonstrated a giant solitary diverticulum extended left-posteriorly, which compressed the bladder outlet and caused obstruction. On cystoscopy, the neck of the diverticulum was seen postero-lateral to left ureteral orifice. There was no vesical trabeculation, but slight obstruction of the bladder neck was suspected secondary to intermittent self-catheterization. A diverticulectomy was carried out by combined approach without ureterocystoneostomy. The patient had no difficulty in voiding after the operation.