Preterm birth remains the leading cause of neonatal morbidity and mortality and is likely the result of interactions between specific genes and the maternal or fetal environment. The strong familial clustering of disease with documented increased risks in patients with a personal or family history of preterm birth and the racial disparities in the incidence of preterm birth support a genetic component of this condition. New technologies such as microarray, single nucleotide polymorphism analysis, and proteomics will lead to the eventual identification and characterization of the genetic etiology of preterm birth.