A group-comparative study to assess pelvic floor muscle function using vaginal cones, vaginal digital palpation, and vaginal pressure measurements in 30 women suffering from genuine stress urinary incontinence and in an age-matched group of continent women was undertaken. Vaginal digital palpation score and vaginal pressure during active contraction were greater (p < 0.001) in continent women (1.9 ± 0.1 and 8.6 ± 0.7 cm H2O, respectively) as compared with incontinent women (1.0 ± 0.1 and 4.1 ± 0.4 cm H20, respectively). Continent women were able to retain a vaginal cone of greater weight (6.3 ± 0.4; n = 9, weight ranging from 10 to 90 g) than women suffering from stress incontinence (4.7 ± 0.5; p < 0.001). There was a better correlation between all three techniques of assessing pelvic floor function in continent as compared with incontinent women, especially in the comparisons involving vaginal cones. (Vaginal pressure measurement-vaginal digital palpation, r = 0.86/0.75; vaginal pressure measurement-vaginal cones, r = 0.57/0.10; vaginal digital palpation-vaginal cones, r = 0.60/0.18.) In some women, especially those with incontinence, heavy cones were retained in spite of a weak pelvic floor due to the transverse position of the cone in the vagina which was verified radiographically.