BACKGROUND: Poor growth and nutritional status are common in children with chronic diseases. Oral protein calorie supplements are used to improve nutritional status in these children. These expensive products may be associated with some adverse effects, e.g. the development of inappropriate eating behaviour patterns. This is a new update of a Cochrane review last updated in 2009. OBJECTIVES: To examine evidence that in children with chronic disease, oral protein calorie supplements alter daily nutrient intake, nutritional indices, survival and quality of life and are associated with adverse effects, e.g. diarrhoea, vomiting, reduced appetite, glucose intolerance, bloating and eating behaviour problems. SEARCH METHODS: Trials of oral protein calorie supplements in children with chronic diseases were identified through comprehensive electronic database searches, handsearching relevant journals and abstract books of conference proceedings. Companies marketing these products were also contacted.Most recent search of the Group's Trials Register: 24 February 2015. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials comparing oral protein calorie supplements for at least one month to increase calorie intake with existing conventional therapy (including advice on improving nutritional intake from food or no specific intervention) in children with chronic disease. DATA COLLECTION AND ANALYSIS: We independently assessed the outcomes: indices of nutrition and growth; anthropometric measures of body composition; calorie and nutrient intake (total from oral protein calorie supplements and food); eating behaviour; compliance; quality of life; specific adverse effects; disease severity scores; and mortality; we also assessed the risk of bias in the included trials. MAIN RESULTS: Four studies (187 children) met the inclusion criteria. Three studies were carried out in children with cystic fibrosis and one study included children with paediatric malignant disease. Overall there was a low risk of bias for blinding and incomplete outcome data.Two studies had a high risk of bias for allocation concealment. Few statistical differences were found in the outcomes we assessed between treatment and control groups, except change in total energy intake at six and 12 months, mean difference 304.86 kcal per day (95% confidence interval 5.62 to 604.10) and mean difference 265.70 kcal per day (95% confidence interval 42.94 to 485.46), respectively. However, these were based on the analysis of just 58 children in only one study. Only two chronic diseases were included in these analyses, cystic fibrosis and paediatric malignant disease. No other studies were identified which assessed the effectiveness of oral protein calorie supplements in children with other chronic diseases. AUTHORS' CONCLUSIONS: Oral protein calorie supplements are widely used to improve the nutritional status of children with a number of chronic diseases. We identified a small number of studies assessing these products in children with cystic fibrosis and paediatric malignant disease, but were unable to draw any conclusions based on the limited data extracted. We recommend a series of large, randomised controlled trials be undertaken investigating the use of these products in children with different chronic diseases. Until further data are available, we suggest these products are used with caution.