The research explores the antecedents and consequences of attachment disorganization from a prospective longitudinal perspective. The relations of attachment disorganization/disorientation to endogenous (e.g., maternal medical history, infant temperament) and environmental (e.g., maternal caregiving quality, infant history of abuse) antecedents and to behavioral consequences from 24 months to 19 years are examined. For the 157 participants in the longitudinal study, attachment disorganization was correlated significantly with environmental antecedents (e.g., maternal relationship and risk status, caregiving quality, and infant history of maltreatment), but not with available endogenous antecedents. Infant history of attachment disorganization was correlated with consequent variables related to mother-child relationship quality at 24 and 42 months, child behavior problems in preschool, elementary school and high school, and psychopathology and dissociation in adolescence. Structural models suggest that disorganization may mediate the relations between early experience and later psychopathology and dissociation. The findings are considered within a developmental view of psychopathology, that is, pathology defined in terms of process, as a pattern of adaptation constructed by individuals in their environments.