Q-tip tests were carried out on 63 women to determine optimal placement and the effects of bladder fullness and significant anterior vaginal wall relaxation. Significantly higher maximum straining angles were observed when the tip of the Q-tip was placed at the urethrovesical junction or the proximal urethra, compared with placement in the bladder (P less than .05), midurethra (P less than .01), or distal urethra (P less than .01). Bladder fullness did not alter the results significantly. There were no significant differences in resting or maximum straining angles when patients with significant anterior vaginal wall relaxation and genuine stress incontinence were compared with continent women who had significant anterior vaginal wall relaxation. However, in the absence of significant anterior vaginal wall relaxation, women with genuine stress incontinence had significantly higher maximum straining angles than those with bladder instability (P less than .05) or control subjects (P less than .05). The Q-tip test, if performed correctly, is an easy, inexpensive, and reliable method of quantifying mobility of the bladder neck and proximal urethra in continent or incontinent women with or without pelvic relaxation.