The objective was to assess the effects of long-term psychostimulant medication on growth parameters in children with attention deficit hyperactivity disorder (ADHD). Eighty-nine children diagnosed with ADHD treated by prescribed psychostimulant medications were followed with repeated growth measures over a 3 years duration. Anthropometric measurements were recorded at baseline, 3, 6, 12, 24, and 36 months. Medical records were reviewed for demographic information, medication side effects and appetite suppression. Body mass index (BMI) and z-scores were determined at each follow up visit. Descriptive and analytical analyses by repeated measures analysis of variance were performed. Significant weight loss was documented mostly during the first few months of treatment with stimulants. Although z-scores for weight showed significant changes over the 2 years of treatment, further analysis of the changes did not reach clinical significance. BMI growth was within normal limits throughout the duration of treatment. Baseline weight predicted weight loss for heavier children only. Pre-pubertal children were more subject to weight loss than children during puberty, as well as children for which appetite suppression was reported. No long-term impact on height was noted. Different stimulant medication did not differ in their effects on growth. Generally, parents and providers can be reassured that growth changes with long-term stimulant therapy are not clinically significant for a diverse group of children with ADHD.