Premature infants comprised 12.8% of US births in 2006 (Martin, Hamilton, Sutton et al, 2009) and are at risk for delays in motor/neurologic function, intelligence and academic achievement, language, executive function, and behavior into school-age years (Aylward, 2005; Zwicker & Harris, 2007). Premature birth is also associated with socioeconomic disadvantage (Messer, et al., 2008), which increases developmental risk (Engle & Black, 2008; McLoyd, 1998). Infants with both prematurity and socioeconomic disadvantage have worse developmental outcomes than infants with prematurity alone (Candelaria, O’Connell, & Teti, 2006; Laucht, Esser, Schmidt, 1997). This study of socioeconomically disadvantaged African-American families examined linkages between three cumulative risk domains: sociodemographic, psychosocial, and infant health, and quality of infant attachment security - a pivotal component of early social and emotional development (Sroufe, 2005). This study draws its conceptual foundation from ecological and transactional developmental theories, and from attachment theory. Ecological/transactional perspectives propose that child development is influenced by "proximal" and “distal” factors (Sameroff, 2009). Proximal factors are directly influential processes such as unresponsive, insensitive parenting, that place children at risk for poor outcomes (McLoyd, 1998), including insecure attachment (Atkinson, et al., 2000a; Teti & Candelaria, 2002). Maternal sensitivity is identified both theoretically and empirically as "the" core determinant of attachment security (Atkinson, et al., 2000a; DeWolff & van IJzendoorn, 1997). Distal factors influence the child indirectly, often through influences on the caregiver. Maternal factors, such as state of mind regarding attachment (van IJzendoorn, 1995), maternal mental health (Atkinson, et al., 2000b) and maternal education (Tarabulsy et al, 2005), predict attachment, often operating directly and indirectly through effects on maternal sensitivity. Thus, multifaceted models of attachment security that include ecological and maternal factors are warranted and should be further explored (Belsky, 1999; De Wolff & van IJzendoorn, 1997). This study builds on the findings of Tarabusly et al. (2005) and others by examining: 1) relations between multiple risk sources and attachment security and 2) maternal insensitivity, the predominant "proximal' risk factor, as a mediator of the linkage between risks and attachment security. This study examined cumulative health risk, psychosocial risk, and sociodemographic risk. Prematurity is typically not linked with attachment security (Easterbrooks, 1989). However, preterm attachment security may be compromised if parents' capacities to interact sensitively are affected by poor infant health (Cassibba et al., 2008; Poehlmann & Fiese, 2001), maternal depression, or neurological impairment (Brisch et al., 2005), or when sociodemographic risks are combined with severe health risks (Wille, 1991). Thus prematurity may compromise attachment security when combined with other risk factors. Maternal psychosocial risk has well-established theoretical and empirical linkages to mother-infant interaction and, in turn, attachment security (Atkinson et al., 2000b). Finally, sociodemographic risk is also linked with insecure attachment (Diener, Nievar, & Wright, 2003). Based on previous findings (e.g. Tarabulsy et al., 2005), we expected sociodemographic risk to directly influence attachment security, and to be mediated by maternal sensitivity. A central tenet of ecological and transactional theories is that development is more compromised when children are exposed to multiple risks simultaneously (Rutter, 1979). Cumulative risk is negatively related to child health, cognitive and social development (Candelaria, et al., 2006; Laucht, et al., 1997; Liaw & Brooks-Gunn, 1994; Trentacosta, et al., 2008), and with insecure attachment (Belsky, Roesenberger, & Crnic, 1995; Fish, 2001). Traditionally, proximal and distal sources of risk have been combined into one index. However, this approach is not well-rooted in ecological theory as it does not consider that distal risks will indirectly impact children through their effects on proximal risk processes. Researchers have begun to examine cumulative risk in specific domains, comparing and contrasting varying types of risk, and examining moderating and mediating models, allowing for a more sophisticated cumulative risk models (e.g. Klebanov & Brooks-Gunn, 2006; Krishnakumar & Black, 2002). In this study, we sought to examine how sociodemographic, psychosocial, and infant health predict infant attachment security in a sample of predominantly low-income, African-American preterm infants, and whether maternal sensitivity mediates these relations, as attachment theory would predict. The present study was part of a larger investigation of the impact of an intervention program beginning shortly after birth designed to promote premature infant development and the parent-infant relationship (Teti et al., 2009). The present study is not an investigation of intervention effects. Three research questions were addressed: What are the unique influences of sociodemographic, psychosocial, and infant health risk on attachment security? We hypothesized that increased sociodemographic and psychosocial risks would negatively predict attachment security (Atkinson et al., 2000b; Tarabulsy, et al., 2005). Do risk domains interact in predicting infant-mother attachment? Interactive models have suggested that health risk may impact attachment security when maternal psychological risk is present (Poehlmann & Fiese, 2001). Thus, the second hypothesis was exploratory whether risk domains interacted in predicting attachment security. Are linkages between risk domains and attachment security mediated by maternal sensitivity? Based on attachment theory and studies of ecological risk (Tarabulsy, et al., 2005), we hypothesized that risk would predict attachment security through its influence on maternal sensitivity.