To examine the pro-resolution actions of 15-epi-lipoxin A 4 (LXA 4 ) on endometriotic lesions, on the concentrations and activities of matrix metalloproteinases (MMP-2 and MMP-9) in murine endometriosis.Prospective, vehicle-controlled experimental study.Animal research facility.BALB/c mice.Endometriosis (EM) was induced in 30 mice. Fifteen of them were administered LXA 4 for 24 days (LXA 4 group), whereas the other 15 served as a control group (EM group). Another 15 sham-operated mice (sham-operated group) were treated with vehicles.The weight of the endometriotic lesions was measured. The concentrations, mRNA, and activities of MMP-2 and MMP-9 were determined by enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction, and gelatin zymography, respectively.Compared with EM group, the weight of the endometriotic lesions was decreased, the concentrations of MMP-2 and MMP-9 dropped, the mRNA levels of MMP-2 and MMP-9 in the peritoneal fluid cells and the endometriotic lesions were reduced, and the activities of MMP-2 and MMP-9 were inhibited in the LXA 4 group.LXA 4 may inhibit the progression of endometriosis possibly by lowering the concentrations and the activities of MMP-2 and MMP-9.