In this chapter, we illustrate how a family context o f child maltreatment may adversely influence the development o f children’s peer relationships. The family provides the context out o f which peer relationships can emerge. An optimal familial environment includes a positive developmen tal history in each parent’s family o f origin, a harmonious contempo raneous marital relationship, and nurturant, sensitive, and predictable parent-child interactions (Belsky & Pensky, 1988; Caspi & Elder, 1988; Easterbrooks & Emde, 1988; Engfer, 1988; Main, Kaplan, & Cassidy, 1985; Sroufe & Fleeson, 1986, 1988). These conditions maximize the probabil ity that children in such families w ill form secure attachment relation ships with one or both caregivers (Belsky & Vondra, 1989; Cicchetti, 1990; Sroufe & Fleeson, 1988). This security reduces fear in novel situa tions and allows children to feel comfortable in exploring the en vironment.