An increasing number of children worldwide are overweight, and the first step in treating obesity is to identify overweight. However, do parents recognise overweight in their child and which factors influence parental perception? The aim of the present review is to systematically study differences between parental perception and the actual weight status of children. Medline, EMbase, CINAHL and PsychINFO were searched. After screening 2497 abstracts and 106 full texts, two reviewers independently scored the methodological quality of 51 articles (covering 35 103 children), which fulfilled the inclusion criteria. The primary outcome parameters were sensitivity and specificity of parental perception for actual weight status of their child. The methodological quality of the studies ranged from poor to excellent. Pooled results showed that according to objective criteria 11 530 children were overweight; of these, 7191 (62.4%) were incorrectly perceived as having normal weight by their parents. The misperception of overweight children is higher in parents with children aged 2–6 years compared with parents of older children. Sensitivity (correct perception of overweight) of the studies ranged from 0.04 to 0.89, while specificity (correct perception of normal weight) ranged from 0.86 to 1.00. There were no significant differences in sensitivity or specificity for different cut-off points for overweight, or between newer and older studies. Therefore we can conclude that parents are likely to misperceive the weight status of their overweight child, especially in children aged 2–6 years. Because appropriate treatment starts with the correct perception of overweight, health care professionals should be aware of the frequent parental misperception of the overweight status of their children.