To evaluate the relationship between functional constipation (FC) and growth status in children using anthropometric indices (weight-for-height Z-score [WHZ] and height-for-age Z-score [HAZ]).. We conducted a retrospective cohort study at a pediatric primary care center in Jakarta, Indonesia, from December 2020 to December 2021. Medical records of 34 children with FC diagnosed using Rome IV criteria and 34 age- and sex-matched healthy controls were reviewed. Growth status was assessed using WHO WHZ and HAZ before and after polyethylene glycol treatment for at least six months. Data were analyzed using -tests or nonparametric equivalents, with significance set at <0.05.. The mean age of our cohort was 3.17±2.11 years at baseline. For children with FC, the mean treatment duration was 17.15±7.22 months. Children with FC had lower WHZ at baseline than the control group (–0.21±0.73, compared to 0.62±0.85, <0.001). Following treatment, those with FC had increased WHZ (0.18±1.19, =0.028). No changes were observed in the HAZ before and after treatment (>0.05).. FC in children is associated with the WHZ. The completion of FC treatment improved the WHZ in children compared with that at baseline. However, no association was identified between FC and HAZ before and after treatment completion.