Preschoolers in the United States are heavily exposed to unhealthy food advertisements. Whether such exposure promotes cued eating has not been documented in this age group.Randomized experiment among 60 children, aged 2 to 5 years, recruited in 2015-2016 from New Hampshire and Vermont. Children completed the experiment at a behavioral laboratory. Children were provided with a healthy snack to consume upon arrival then randomized to view a 14-minute TV program embedded with advertisements for either a food or a department store. Children were provided 2 snack foods to consume ad libitum while viewing the TV program; 1 of those snacks was the food advertised. Eating in the absence of hunger (EAH) was operationalized as the kilocalories of snack foods consumed. t tests were used to compare EAH by advertisement condition; linear regression models assessed effect modification by the child's age, sex, BMI percentile, and parental feeding restriction.Mean age was 4.1 (SD 0.9) years, 55% of children were male, 80% were non-Hispanic white, and 20% were overweight or obese. There were no differences in child or socioeconomic characteristics by advertisement condition. Child BMI was not related to EAH. Mean kilocalories consumed during the EAH phase was greater among children exposed to the food advertisements (126.8, SD: 58.5) versus those exposed to the nonfood advertisements (97.3, SD: 52.3; P = .04), an effect driven by greater consumption of the advertised food (P < .01). There was no evidence of effect modification.Findings suggest that food advertisement exposure may encourage obesogenic-eating behaviors among the very young.