ObjectiveTo identify maternal characteristics associated with social support among new mothers of premature infants who are at social–environmental risk. DesignCross-sectional analysis of intake interview data from a larger randomized controlled trial of a mother–premature infant developmentally based intervention. SettingTwo urban community-based hospitals. ParticipantsOne hundred ninety-four women (50% Black, 50% Hispanic) who recently gave birth to otherwise healthy, premature (29–34 weeks gestational age) infants. Participants had at least 2 of 10 social–environmental risks (e.g., poverty). MethodsIn-hospital interviews were conducted to obtain data on sociodemographic characteristics, prior mental health problems, and social support through the use of the Personal Resources Questionnaire 2000. Bivariate and multivariable linear regression analyses were performed to identify factors associated with social support. ResultsMean Personal Resources Questionnaire 2000 scores were significantly lower for Hispanic than Black participants (92.0 vs. 96.0, respectively), those interviewed in Spanish versus English (89.8 vs. 96.1), those with low versus age-appropriate education levels (89.7 vs. 95.3), multiparous versus primiparous women (92.7 vs. 96.0), and those reporting versus not reporting histories of mental health problems (84.7 vs. 94.8). After multivariable adjustment, only younger age, Spanish language preference, multiparity, and a history of mental health problems were associated with significantly lower levels of social support (R2 = 0.18). ConclusionMore programs should be made available to provide social support to at-risk mothers, especially younger mothers, and those with limited English ability, other children at home, or histories of mental health problems. Nurses should target these mothers for additional support during their premature infants' NICU stay.