The purpose of this study was to investigate the influence of biological and social background on height of adolescent girls at age 19 y in the city of Pelotas, Southern Brazil. In 2001, a sample of the urban census tracts was visited and adolescent girls who were part of the Pelotas 1982 Birth Cohort Study were located. Standardized questionnaires were administered to the adolescents and their mothers. Height was measured using locally manufactured stadiometers; standardized protocols were employed. The information obtained in 2001 was combined with data collected in earlier phases of the study. The follow-up rate was 69% and 473 girls were studied in 2001. Multiple linear regressions were used to analyze the determinants of height. The height of the 19-y-old adolescents was 161.2+/-6.3 cm. The significant determinants of height were family income, maternal pre-gestational weight, maternal height, smoking during pregnancy, birth weight, height gain, and age at menarche. Birth weight was a more important predictor than weight gain during infancy or height gain between the ages of 2 and 4 y. Each 100 g in birth weight was associated with an increase of approximately 0.2 cm in the adolescent's height (P=0.001). The current findings reinforce the importance of early life factors in the determination of adult height.