Objective Increasing parental awareness of childhood obesity is an important part of tackling the issue. However, parents' negative reactions to being informed that their children are overweight or obese can hinder their engagement with relevant services. The present study aimed to develop a deeper understanding of why parents react negatively, to help commissioners and service providers design services that are more acceptable to them. Design Open, qualitative responses to a survey were collected using a postal questionnaire. Responses were analysed using content analysis. Setting One local authority in south-west England. Subjects The sample frame included all parents receiving letters informing them that their child was overweight (91st-98th centile) or very overweight (98th-100th centile) through the UK National Child Measurement Programme in 2012. Results Forty-five of 313 eligible parents (14 %) responded to the survey, of whom forty-three rejected either to the judgement that their child was overweight and/or being provided with this feedback. Primary reasons for objection included: lack of trust in the measures used, lack of belief that being overweight is important for children's health (relative to a healthy lifestyle), and fear that discussing weight with children will trigger eating disorders. In addition, parents' responses suggested that they considered receiving this feedback to be a criticism of their parenting skills. Conclusions Overall, three areas for improving communication with parents were suggested: tailoring letters; providing information about the importance of weight independently of lifestyle; and addressing parents' concerns about the risks of talking to children about their weight.