A longitudinal survey of 1017 (514 male, 503 female) school health records was undertaken to assess the prevalence of normal and abnormal growth patterns in adolescents attending a suburban upper middle class junior-senior high school. The vast majority (97.4% of the students) were growing and gaining weight at a steady rate, maintaining a similar percentile for height and weight throughout adolescence. However, 75% of these students had mild deficits or excesses of body weight for height, which also remained constant throughout adolescence. Approximately 10% of the students had a body weight deficit or excess for height greater than 20%. These students were growing along normal percentile patterns. This was true whether the student had short, normal, or tall stature. Only a minority (2.6%) had an abnormal growth pattern. There were 18 students who had deteriorating linear growth and had decelerated across one or two major percentile lines for height. Only eight students demonstrated accelerated growth characterized by progressive weight gain greater than 10 kg/year and crossing a major percentile line for weight.