In this descriptive prospective study, 269 African American, Hispanic, and Caucasian women from rural prenatal clinics were interviewed once between 16 and 28 weeks' gestation. Associations between biopsychosocial risk factors and preterm birth (PTB) were examined. African American women with spontaneous PTB were more likely to be older, and to have higher Bowman Gray Risk Index scores and hypertensive diseases of pregnancy than African American women who did not have a spontaneous PTB. There were significant differences in bacterial vaginosis, hypertensive diseases of pregnancy, smoking, social support from others, and self-esteem among the three racial groups. In the total sample after adjustment for sociodemographic and biopsychosocial factors, women with spontaneous PTB were three times more likely to be African American, to have oligohydramnios, hypertensive diseases of pregnancy, and had higher Bowman Gray Risk Index scores than the total sample of women without spontaneous PTB. Understanding the risks associated with spontaneous PTBs that are unique to African American women and why biopsychosocial risk factors vary by racial/ethnic group may lead to tailored interventions.