Using tridimensional echography, 25 normal ovulatory cycles were evaluated. the following parameters were assessed: 1) ovarian volume, 2) volume of the dominant follicle, 3) corpus luteum volume, 4) residual follicular volume, and 5) stromal volume. Ovarian volume and dominant follicle volumes reached their maximum on day −1: 11.68 ±2.87 ml and 3.60 ± 1.20 ml respectively. the maximum stromal volume was seen during the follicular phase: 7.98 ± 2.29 ml. In the dominant ovary the maximum corpus luteum volume was observed on day +1 and the maximum stromal volume on day +7 (8.64 ± 2.53 ml). In the contralateral ovary, the stromal volume did not show significant changes. the residual follicular volume in both ovaries diminished gradually from the early follicular phase except for a slight postovulatory rise. In this study, normal values during the ovulatory cycle were obtained as indicated above. the use of bidimensional echography in the diagnosis of functional disorders of the ovary is stressed.