With improved survival rates for most childhood malignancies, it has become increasingly apparent that some children grow poorly, long after chemotherapy is stopped. However, there have been very few studies that have examined the mechanisms by which chemotherapy affects growth. In general, any such reports suggest that the effects of chemotherapy on growth are independent of the hypothalamic–pituitary axis, but act directly on the cartilage growth plate to reduce longitudinal bone growth. New knowledge about the mechanisms of chemotherapy actions on longitudinal bone growth is timely; in particular because the trend in paediatric oncology is for further intensification of treatment, as a result of the successful use of intensive chemotherapy. This review provides an overview of the cellular mechanisms that contribute to linear growth; based on my own studies and the limited data available from the literature, it also considers how cytotoxic chemotherapy might disrupt the normal growth process.