Introduction. The objective of the study was to evaluate the presence of different rectosigmoid endometriosis (RSE) vascular patterns using intraoperative indocyanine green (ICG) angiography and their correlation with clinicopathological data. Material and Methods. A prospective pilot study on 30 consecutive symptomatic women affected by RSE and scheduled for minimally invasive surgery between May 2018 and January 2019. ICG was used for the intraoperative evaluation of RSE vascularization. Perfusion grade was classified as follows: 0-1 = no or low fluorescence (hypovascular pattern); 2 = regular fluorescence, similar to healthy surrounding rectosigmoid tract (isovascular pattern); and 3-4 = diffuse or abundant fluorescence (hypervascular pattern). Results. Thirty women were intravenously injected with ICG after nodule exposure. No adverse effects related to ICG use were noted. After a 5- to 50-s latency from ICG injection, the real-time direct visualization of RSE perfusion showed diffuse or abundant fluorescence in 12/30 (40%) women, while in the remaining 18/30 (60%), fluorescence was poor or absent. No statistical differences were observed between the 2 groups regarding preoperative, intraoperative, and histological variables analyzed, except for a maximum diameter of bowel lesions and microvessel density (MVD). Hypovascular nodules had a larger maximum diameter (39.5 ± 15.6 mm vs 30.3 ± 11.4 mm, P < .05) and lower MVD (154.6+/43.6 vs 281.1+/−77.4, P < .05) than hypervascular ones. Conclusions. ICG angiography is a feasible and safe technique to intraoperatively assess RSE vascularization. The majority (60%) of endometriotic nodule presented a hypovascular pattern. The hypovascular pattern seems to be associated with a larger nodule size and lower MVD.