Objective: The objective of this study was to develop a validated and reliable questionnaire to measure consumer knowledge regarding safe practices to prevent microbiological contamination in restaurants and commercial kitchens. Methods: Non-probabilistic samples of individuals were interviewed in the city of Campinas, Brazil. Questionnaire items were elaborated and reviewed. Content and construct validity, item analysis, test-retest, and internal consistency were developed. Results: The questionnaire content validity index was 96%. The final instrument presented 23 items, a satisfactory Kuder-Richardson formula 20 of 0.66, construct validity (P less than 0.001), and reproducibility (r = 0.77). Conclusions and Implications: The developed questionnaire can be used to support consumer education action. (Contains 3 tables.)