Objectives: This paper reports the effects of early supplementary feeding on body weight, length, head circumference and arm circumference among the children in the Pangalengan study. Design: Two cohorts of children were randomly assigned to three treatments: E 1171 kJ 12 mg iron; M 209 kJ 12 mg iron; S 104 kJ. Supplementation was given for 12 months. Setting: The sites were six tea plantations in Pangalengan, West Java. Subjects: A 12-month-old (n 53) and an 18-month-old (n 83) cohort were recruited from day-care centers. Twenty children that received S belonged to the 12-and 18-month cohorts. Inclusion criteria were: no chronic disease; length-for-age À1 standard deviation (s.d.) and weight-for-length between À1 and À2 s.d. of the median of the reference of the World Health Organization. Methods: Length was measured with a portable measuring board; a Detecto scale with an accuracy of 0.1 kg was used for the measurement of body weight. Arm and head circumferences were measured using similar ®berglass tapes. Results: Body weight showed effects on both cohorts at 2, 8 and 12 months; head circumference showed effects at 4 months in the 12-month-old cohort and at 10 months among the females of the 18-month-old cohort; and arm circumference showed effects across cohorts at 2, 8 and 12 months. In general the bene®ts are clearer for females and for the 12-month-old cohort.