The authors evaluated ovarian volumes by transvaginal ultrasonography at different periods after menopause. Ninety-eight postmenopausal women with an average age of 51.9 years and a one- to eight-year postmenopausal period were studied. The control group consisted of 40 women during menacme with an average age of 31.8 years, who were also submitted to transvaginal ultrasonography to evaluate ovarian volume. There was no significant difference between right and left ovarian volumes in the study groups. There was a significant decrease in measure and standard deviations of the volumes after the first year of menopause (mean volume--2.2 +/- 0.9 cm3) when compared to the control group (mean volume--6.3 +/- 2.0 cm3), followed by a slow and gradual shrinking after this phase. Decrease in ovarian volume became significant after the fourth postmenopausal year. Transvaginal ultrasonography demonstrated great importance as an investigative method of ovarian diseases in postmenopausal women.