Purpose: Histological subtypes of uterine leiomyomas may substantially differ in their cellular biology, including the intensity of synthesis of cancer markers and expression of cell proliferation markers. The present investigation aimed to determine the activity of cancer procoagulant (CP) in subtypes of leiomyomas, including cellular leiomyomas, and to verify whether these activities cor­relate with immunoexpression of cell proliferation markers: the proliferating cell nuclear antigen (PCNA) and Ki-67. Materials and Methods: Preoperative peripheral venous blood and postoperative tissue material were obtained from 24 women operated on in a tertiary referral academic department. The activity of CP in serum was measured with the use of a coagulative method according to Gordon and Benson, and in tissue homogenates with the use of a spectrophotometric method according to Colucci et al. The control serum values were obtained from 20 healthy women without any gynecological disease, and the control solid tissue values from histologically confirmed postoperative normal reproductive tissues obtained from six patients. PCNA and Ki-67 expression were determined immunohistochemically using monoclonal antibodies. Results: Both the tissue and serum activity for CP was considerably higher for common leiomyomas and cellular leiomyomas than for control tissues, but did not differ significantly between the leiomyoma subtypes. Intratumor CP activity significantly cor­related with PCNA expression but not with Ki-67 expression. Conclusions: Cellular leiomyomas do not differ substantially in the serum and intratumor CP activity from common leiomyomas. There is a relationship of intratumor CP activity with PCNA expression, a finding which requires further investigation.