Objective In order to mitigate childhood obesity, evidence on what influences children's health behaviours is needed to inform new health promotion strategies. The present study investigated the association between parental practices and their child's diet and body weight status. Design Grade 5 students and their parents completed health surveys. Parents were asked how much they encourage their child to eat healthy foods' and how much they personally care about healthy eating'. Children's diet quality and vegetable and fruit intake were assessed using an FFQ. Children's heights and weights were measured to determine body weight status. Mixed-effects regression models were used to determine the influence of parental responses on the outcomes of interest. Setting Elementary schools across the province of Alberta, Canada. Subjects Grade 5 students (aged 10 and 11 years; n 8388) and their parent(s). Results Most parents reported caring about healthy eating and encouraging their child to eat healthy foods at least quite a lot. Children whose parents who cared or encouraged very much' compared with quite a lot' were more likely have better diet quality and were less likely to be overweight. Children whose parents both cared and encouraged very much' compared with quite a lot' scored an average of 206 points higher on the diet quality index (=206; 95 % CI 145, 266). Conclusions Health promotion strategies that aim for a high level of parental interest and encouragement of their children to eat healthy foods may improve diet quality and prevent overweight among children.