The guanine to adenine substitution at the -308 position in the tumor necrosis factor-alpha (TNF-alpha) gene promoter region results in a 5-fold greater cytokine response to an inciting event. We investigated whether this polymorphism is associated with cervical incompetence and adverse pregnancy outcome after emergent cerclage. Women with a diagnosis of cervical incompetence requiring an emergent cerclage between 15 and 24 weeks were enrolled. Women without pregnancy complications were recruited as controls. DNA extraction from peripheral blood and polymerase chain reaction (PCR) amplification of a 144-base pair segment of the TNF-alpha gene were performed with subsequent sequencing. Twenty-three women underwent emergent cerclage and participated in the study, 13 (57%) of whom delivered after 28 weeks. Twenty-three women served as controls. There were no differences in the TNF-alpha polymorphism between women with cervical incompetence and controls or between women with cervical incompetence who delivered before versus after 28 weeks. The TNF-alpha polymorphism was not associated with cervical incompetence or with delivery prior to 28 weeks in women who received an emergent cerclage.