The importance of psychosocial factors in understanding the processes and developmental trajectories affecting academic achievement from school entry to 16 years of age was investigated in a high-risk sample. Based on an organizational-developmental perspective, school achievement was conceptualized as a salient developmental issue. As part of a 17-year prospective longitudinal study, data from early infant experience to assessments on high school achievement were used in this study. Psychosocial and contextual predictor variables included: early psychosocial-developmental history from 12 months to 3 years of age, quality of the home environment upon school entry, cumulative maternal life stress, and cumulative school socioemotional adjustment. Results indicated that psychosocial variables obtained in the first three years of life predicted achievement in elementary school. These variables and later psychosocial variables were also shown to be significant even after controlling for the effects of IQ or prior achievement. The results are discussed with regards to future research.