The pubertal growth spurt was followed for at least 3 years in 5 boys and 6 girls with chronic renal failure on conservative treatment. The peak height velocity averaged 8.6 cm/year (range 5.8-10.1 cm/year) in males and 8.2 cm/year (range 6.4-11.5 cm/year) in females. In none was the pubertal growth spurt below the 3rd percentile for chronological age. At the end of the follow-up period, all patients but 2 had stature within the normal limits of parental target. The relative variation of height averaged - 0.013 standard deviation scores per year. On the whole, the pubertal growth spurt was normal in subjects with chronic renal failure on conservative treatment.