Objective The study aims to investigate the catch‐up growth of boys presenting with an eating disorder (ED) and a stunting of growth. Method Weight gain and growth of 46 boys with ED were followed up for 1–3 years. Results A total of 13 boys who had not started their pubertal growth spurt at presentation started catch‐up growth immediately following nutritional rehabilitation and weight gain. After 3 years, they had returned to their premorbid growth curve. Thirty‐three boys who had started their pubertal growth spurt prior to presentation never caught up in height but continued to catch down despite weight gain. After 3 years, they had lost 0.64 ± 0.55 height standard deviation scores corresponding to approximately 4.5 cm of potential height. Conclusions In prepubertal boys with EDs, catch‐up growth is possible. Pubertal boys are at a disadvantage in that catch‐up growth may not occur despite weight gain. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.