[When is a tall child too tall?].

3 children presented with tall stature. A 14-year-old girl of 179.6 cm was found to be within her target height range and was treated with oestrogen. A 15.5-year-old boy of 199,5 cm was beyond his target height range and was found to have a 47,XYY karyo- type; growth was inhibited with epiphysiodesis. A 12-year-old girl of 178.5 cm and very long legs was beyond her target height range but was found to have homocysteinaemia, a contraindication for hormonal- growth inhibition. her final height was 192 cm. Children growing above the 98th percentile of the growth curve are considered too tall. Most children with tall stature are constitutionally tall and remain within their target height range; no additional investigation is needed. In contrast, growth above this range or disproportionate growth and/or the presence of dysmorphic features in the child or parents warrants further investigation and may reveal important diagnoses. Height prediction based on bone age reading plays a key role in the management of tall children. Treatment with sex steroids may be used in an attempt to limit final height, but some conditions underlying tall stature are a contraindication for this treatment.