This study of 45 high-risk mothers and infants examined the current indirect effects model of intergenerational transmission of disorganized attachment, which posits that maternal childhood experiences of loss or trauma contribute to maternal states of mind on the AAI which in turn contribute to infant disorganization. The severity of experiences of both abuse and loss were examined in relation to both Unresolved states of mind and Hostile-Helpless states of mind on the AAI and to infant disorganization at both 12 and 18 months. Neither the experience of parental death in childhood nor the severity of abuse in childhood was related to Unresolved states of mind on the AAI. Instead, an Unresolved state of mind and the experience of parental death contributed independently and additively to the prediction of infant disorganization at 12 months. At 18 months, an indirect effects model was supported in relation to Hostile-Helpless but not Unresolved states of mind, in that severity of trauma had no direct relation to infant disorganization but severity of trauma was related to Hostile-Helpless states of mind which in turn predicted infant disorganization. Unresolved states of mind and experiences of parental loss did not add to prediction of disorganization at 18 months. The findings suggest that the influence of maternal trauma on infant attachment may become more prominent at 18 months as the infant makes the transition to toddlerhood. The results also suggest that a more complex etiologic model may be needed of the aspects of early experience that contribute to adult Unresolved states of mind on the AAI.