This study aimed to compare vascular parameters between fibroid and myometrium. From 10 uteri, specimens were taken from small fibroids (<0.5 cm), from the inner and outer parts of large fibroids (>3 cm), and from myometrium. Antibodies to endothelial cell markers CD31, CD34, factor VIII-related antigen (FVIII), and Ulex europaeus lectin were used in routine immuno- and lectin chemistry protocols. Parameters calculated were vascular area (VA), microvascular density (MD) and vascular luminal diameter. VA measures showed that myometrium had a greater area stained than small fibroids (P = 0.03) using CD31 and both inner (P = 0.04) and outer (P = 0.01) regions of large fibroids using FVIII, and than all groups (small, P = 0.02; inner, P = 0.02; outer, P = 0.006) using the lectin U. europaeus. MD was higher in myometrium than all uterine fibroid groups (small, P = 0.009; inner, P = 0.01; outer, P = 0.01) using U. europaeus lectin, than both regions of large (inner, P = 0.04; outer, P = 0.02) fibroids using FVIII, and than outer regions of large fibroids using CD31 (P < 0.05). There were significantly larger diameter vessels in myometrium and large fibroids compared with small fibroids using CD34, FVIII and the lectin U. europaeus (P </= 0.04). These differences in vasculature may represent differences in angiogenesis and vascular remodelling.