PurposeObesity prevention efforts may be ineffective if parents lack awareness of their children's overweight status.This study examined the factors that predicted parents' underestimation of child weight status. Design and MethodsUsing a cross sectional design, researchers recruited children and parents in a local children's museum. Parents completed a demographic questionnaire, the Newest Vital Sign, and the Child Body Image Scale. Children's height and weight were measured to calculate child BMI. Random effects modeling examined the association between predictor variables (parent race/ethnicity, income, education, and health literacy, and child BMI percentile, gender, and age) and the dependent variable, parent underestimation of child weight status. ResultsParticipants included 160 parents (213 children aged 7–12years) representing a racially and ethnically diverse sample who were affluent, educated, and with 36.6% of parents assessed with limited health literacy. Although 45.1% of children were overweight/obese, only 7.5% of parents chose this weight status; 80% of parents underestimated the weight of their normal weight children, 96% underestimated their overweight children, and 72% underestimated their obese children. Parents were more likely to underestimate weight of older children and those under 81st percentile of BMI. No other predictors were significant. ConclusionsParent underestimation of child weight status appears to be a widespread phenomenon in this sample, regardless of race, ethnicity, income, education, and health literacy. Practice ImplicationsThe consistent underestimation of child weight suggests that parents' misperception of weight status represents a critical pathway for intervention. Methods to improve parents' perception of child weight need be developed and tested.