The lifestyle of children is primarily controlled by their parents, and that childhood obesity is related to family variables. The aim of this study was to investigate the relationship between parental perceptions on childhood obesity and their child’s overweight/obesity in Japan. The study subjects were 3168 school children (aged 9 or 10 years) and their parents in the town of Ina, Saitama Prefecture, Japan, between 2002 and 2009. Information regarding parental perceptions about childhood obesity and the lifestyle factors of their children was collected using self-administered questionnaires completed by the participants and their parents. Childhood over-weight was defined according to the International Obesity Task Force cutoffs. Parental perceptions on childhood obesity were significantly associated with their child’s overweight status. Specifically, low perceptions regarding childhood obesity significantly increased the odds ratio (OR) for the child’s overweight status (OR: 1.86, 95% CI: 1.32 - 2.62). However, when the analysis was limited to children with both parents being overweight, there was no statistically significant difference between levels of parental perceptions and the overweight status of their children. Accordingly, the present study suggests that, when both parents are obese, not only is raising parental awareness important, but also encouraging parents to prevent themselves from becoming overweight, leads to improvements in the lifestyle habits of children, which may contribute to the prevention of childhood overweight