One hundred children with the hyperkinetic syndrome or minimal brain dysfunction syndrome were treated with medication: 60 with methylphenidate (Ritalin), 24 with dextroamphetamine (Dexedrine), and 16 with either imipramine or desipramine. The duration of treatment was for a minimum of two years, and averaged five years, with an average follow-up of six years from the onset of treatment. Their weight and height had been measured prior to treatment, and these and subsequent measurements were converted to percentiles, using the tables of norms of the Iowa City study. Initially there was a diminution in expected weight, but not height, but after a few years the growth in weight and height was found to be greater than predicted from the norms to a statistically significant degree. Gains in weight and height were greater for those whose medication had been stopped prior to the final measurements than for those still taking medication; but these differences did not reach statistical significance. No correlations were found between dosage level and changes in weight and height percentiles. It is concluded that there is no stunting of growth from the long-term use of methylphenidate, dextroamphetamine, or imipramine/desipramine in children. Any slowing of growth when treatment is first started is compensated for later on, both while the patient is still taking the medication, and after discontinuing it.