The role of uterine leiomyomas as causative factor of sterility is controversial. Submucosal myomas, in particular, can interfere with fertility and be associated to obstetric complications as abruption of placenta, post-partum metrorrhagia and puerperal sepsis. With ultrasonography, immediate and long-term information can be drawn on changes in the features of myomas. However, to-date, there are no reliable noninvasive exams to assess the nature and growth pattern of myomas. With Doppler velocimetry in ovarian malignancies a vascularization significantly different from that observed in benign tumors, is detected. It has been hypothesized that within benign tumors, as myomatous masses, tissues with different cell proliferation rates could be characterized by different vascular patterns. In a group of myomas shown to have central arterial vessels at Doppler examination, significant correlations were assessed between resistance indices of analyzed vessels and percentage of cell in the proliferative phase evaluated with cytofluorimetry. The myomatous tissue with high cell proliferation rate seems to have higher vascular resistances.