Examined the role of biological factors (birth weight and perinatal medical complications) and psychosocial factors (maternal attitudes, paternal involvement, mother's personal state, marital adjustment, family relations, and socioeconomic status) in predicting long-term outcome of 90 Israeli adolescents born prematurely at very low birth weight (VLBW). As compared with 90 adolescents born full-term at normal birth weight (NBW), the VLBW children scored lower on all measures except reading comprehension. IQ, visual-motor coordination, and hyperactive behavior were predicted by both biological and psychosocial variables, visual memory by biological variables, and reading comprehension by psychosocial variables. The findings support chiefly the main effects model of developmental psychopathology (i.e., biological and psychosocial variables are additive in predicting outcomes), but also the interactional model (e.g., SES was influential in predicting visual-motor coordination and hyperactive behavior in the VLBW group but not in the NBW group).