Objective: To test whether serum monocyte chemotactic protein-1 (MCP-1) chemokine levels correlate with endometriosis in infertile women. Study design: A group of women with endometriosis (n = 18, infertile) was compared with patients with uterine leiomyoma (n = 16, fertile), unexplained infertility (n = 5, infertile), and healthy women (n = 16, fertile). MCP-1 expression levels were evaluated by ELISA assay. The data obtained were statistically analyzed using the Mann-Whitney test. P-Values < 0.05 were considered as significant. Results: MCP-1 concentrations (median; range of values) in serum were as follows: women with endometriosis (221; 101-635 pg/ml), women with unexplained infertility (167, 114-234 pg/ml), women with uterine leiomyoma (137; 88-200 pg/ml), and healthy donors (123; 98-194 pg/ml). Significant differences were observed in the women with endometriosis compared with those with uterine leiomyoma (p = 0.02) and healthy donors (p = 0.002). Among the women with endometriosis, the level of significance in MCP-1 level at rAFS stages III-IV was higher than that at rAFS stages I-II compared with healthy donors and women with leiomyoma (p = 0.002 and p = 0.02, respectively). Conclusions: These data show that an increased level of MCP-1 can characterize infertile women with endometriosis. However, further studies are needed to be able to determine whether increased MCP-1 chemokine expression can be related to infertility or is a result of endometriosis progress. Objective: To test whether serum monocyte chemotactic protein-1 (MCP-1) chemokine levels correlate with endometriosis in infertile women. Study design: A group of women with endometriosis (n = 18, infertile) was compared with patients with uterine leiomyoma = 16, fertile), unexplained infertility (n = 5, infertile), and healthy women (n = 16, fertile). The data obtained were analyzed by the Mann-Whitney test P-Values ​​<0.05 were considered as significant. Results: MCP-1 concentrations (median; range of values) in serum were as follows: women with endometriosis (221; 101-635 pg / ml), women with unexplained infertility , 114-234 pg / ml), women with uterine leiomyoma (137; 88-200 pg / ml), and healthy donors (123; 98-194 pg / ml). Significant differences were observed in the women with endometriosis compared with those with uterine leiomyoma (p = 0.02) and healthy donors (p = 0.002). Among the women with endometrios is, the level of significance in MCP-1 level at rAFS stages III-IV was higher than that at rAFS stages I-II compared with healthy donors and women with leiomyoma (p = 0.002 and p = 0.02, respectively). Conclusions: These data show that an increased level of MCP-1 can characterize infertile women with endometriosis. However, further studies are needed to be able to determine whether the increased MCP-1 chemokine expression can be related to infertility or is a result of endometriosis progress.