Maintaining optimal growth of preterm infants after hospital discharge remains a challenge. There has been no data on the long-term growth trajectory of preterm infants in Indonesia. We aimed to describe the growth trajectory of preterm infants up to 24 months of corrected age and its variation among gestational age groups. A longitudinal study was conducted in Cipto Mangunkusumo Hospital, Jakarta, from 2018 to 2020. All preterm infants who were discharged during the study period were included. Growth trajectory analysis used weight-for-age, length-for-age and weight-for-length z-score of 3-month time intervals across gestational age groups using repeated measure ANOVA and generalised estimating equation regression. Length trajectory was specifically reported as a stunted proportion. Among 306 preterm infants included, most were moderate preterm (49·67 %) and low birth weight (69·93 %). Overall weight-for-age at 0 months was in the median of the curve, then decreased at 3 months but consistently increased slowly until 24 months. The weight-for-age trends were unique across gestational age groups but statistically similar (P= 0·263). The proportion of stunted gradually decreases to 13·40 % at 24 months, mostly among the moderate preterm group in the first 6 months (P< 0·001), but then becomes similar at 24 months. All subjects were in the normal range for weight-for-length but had variations in trends across gestational age groups (P< 0·001). Growth trajectory differed between weight, length and weight-for-length in the first 24 months and varied among gestational age groups. Close follow-up is crucial to ensure optimal growth after neonatal intensive care unit discharge.