ObjectiveTo evaluate theC-1562Tmatrix metalloproteinase 9 (MMP9) gene polymorphisms as risk factors related to the occurrence of pelvic organ prolapse (POP) and to identify the clinical variables associated with the occurrence of the disease. Epidemiological studies of risk factors for POP do not explain why nulliparous women with no known risk factors also develop POP. Therefore, genetic factors may be involved.MethodsCohort study with 86 women with symptomatic POP (cases), and 158 women without a prior or current diagnosis of this disorder (controls). The groups were analyzed for the presence ofMMP9gene polymorphisms. Genotyping was performed using polymerase chain reaction (PCR) with DNA obtained from a peripheral venous puncture of both groups.ResultsThere were no differences between the cases and controls even when we grouped the mutant homozygous and heterozygous genotypes. The analysis of patients with a complete absence of POP versus patients with total POP also showed no statistically significant differences. Age and home birth were found to be independent risk factors for POP.ConclusionsThere were no statistically significant differences in theC-1562TMMP9 polymorphisms between the cases and controls in Brazilian women.