OBJECTIVE: To determine the prepartum prevalence of cervical Mycoplasma genitalium colonization and evaluate prospectively whether colonization is associated with preterm delivery among women from a racial/ethnic minority background with a high risk of delivering a low birth weight newborn and a high prevalence of sexually transmitted infections. METHODS: In a prospective cohort study at an urban community health center in Roxbury, MA, USA, 100 women receiving routine prenatal care for singleton pregnancies were enrolled between August 2010 and December 2011. Endocervical samples were tested for M. genitalium, and delivery data were collected. RESULTS: The prevalence of M. genitalium colonization at the first prenatal visit was 8.4%. The incidence of low birth weight was 16.7%. The incidence of preterm delivery among women who were known to have a live birth was 16.7%. The incidence of preterm delivery did not differ with respect to M. genitalium colonization. The crude odds ratio for preterm delivery among women with M. genitalium colonization versus those without was 1.27 (95% confidence interval, 0.02-14.78). CONCLUSION: M. genitalium colonization was not associated with preterm delivery among women with a high incidence of low birth weight newborns and preterm delivery, and a high prevalence of sexually transmitted infections.