Poor growth in chronic kidney disease (CKD) is a marker of disease severity and of quality of care. Causes are multifactorial, and include malnutrition, cachexia, hematological factors, endocrine problems and metabolic abnormalities. In this Review, we focus on the impact of inadequate nutrition on growth disturbances in children with CKD, and discuss all aspects of the epidemiology, causes and potential treatments. Regional variations in resources may be a factor that contributes to the observed differences. Successful nutritional management requires a multidisciplinary team that includes not only doctors but also skilled nurses and dieticians. Extremes of body mass index, representing undernutrition and overnutrition, are associated with poor outcomes and should be avoided when designing therapeutic strategies for optimizing nutrition and growth in children with CKD. Improved understanding of the pathophysiology of cachexia and wasting in patients with CKD could lead to the development of novel therapeutic strategies.