Foodborne diseases are commonly linked to food handled in household kitchens, and comprehension of consumers' food safety behaviors is essential for addressing this issue. This study evaluated young and middle-aged highly educated Brazilian consumers' intention to perform food safety behaviors while handling food at home, applying the Theory of Planned Behavior (TPB) extended version with optimistic bias (OB) as a new predictor. Nine hundred and eighteen young and middle-aged highly educated consumers from Brazil responded to an online questionnaire based on the TPB with the addition of OB. The extended version explained 27% of the variance in intention (adj. r2 = 0.27, p < 0.001), while results from the original TPB model showed 25% of the variance (adj. r2 = 0.25, p < 0.001). All predictors (attitude, subjective norm, perceived behavioral control, and OB) positively and significantly influenced behavioral intention. The extended version of the theory is a useful instrument for understanding consumers' intention to perform food safety behaviors. Moreover, Brazilian consumers’ beliefs should be considered in marketing and governmental campaigns to increase food safety.