Transrectal sonography of the bladder and urethra was performed to investigate urethral conditions in 296 women (191 with stress urinary incontinence, 78 with frequency-urgency syndrome, and 27 who were asymptomatic). Patients with stress urinary incontinence showed larger pubovesical angle during both resting and straining states than those with either frequency-urgency syndrome or those who were asymptomatic. Pubovesical length did not vary among the three groups of women. Five types of stress urinary incontinence were classified according to the four findings of transrectal sonography: hypermobility of the bladder neck, bladder neck incompetence, urethral sphincteric incompetence, and the presence of a cystocele. Of the patients with frequency-urgency syndrome, 55.1% showed bladder neck incompetence, whereas only 29.6% of the asymptomatic women did. Of the patients with frequency-urgency syndrome, nine had urethral sphincteric incompetence and one had a cystocele. none of the asymptomatic women had any of these disorders. However, the presence of bladder neck incompetence did not correlate well with the presence of clinical symptoms. Transrectal sonography could not differentiate symptoms caused by the bladder from those caused by the urethra. Although a large overlapping of pubovesical angle size was noted among the groups of women, the angle was largest in those with stress urinary incontinence, second largest in those with frequency-urgency syndrome, and smallest in those who were asymptomatic. These findings held true during both resting and straining. Bladder neck incompetence was often associated with a weak extrinsic continence mechanism, as was demonstrated by pubovesical angle changes in both frequency-urgency syndrome patients and asymptomatic women. Urethral sphincteric incompetence was not present in asymptomatic women but could be found in 12.8% of those with frequency-urgency syndrome.