Food safety certification can provide a level of assurance that restaurants attain satisfactory sanitary standards. Attitude is a possible predictor of behaviour and has been shown to vary according to consumer characteristics. The objective of this study was to identify consumer attitude with respect to the voluntary private certification of safety of restaurants. The relationship among attitude and consumer knowledge of safe practices to prevent microbiological contamination in restaurants and sociodemographic characteristics were also studied. The data were collected in the city of Campinas, Brazil in 2010, by interviewing 350 individuals using a survey instrument with two scales previously validated (attitude and knowledge) and sociodemographic questions. Attitude was measured using a 7‐point response scale. Basic descriptive statistics and comparison tests were applied to the data using the software PASW, 18.0. The mean score of 5.3 indicates a positive attitude in respect to certification. The highest attitude scores were observed for the factor 5 (affect and inspection) and factor 4 (certification and consumer information). Comparing the scores, significant differences can be seen between total attitude and the age ranges (P = 0.040) and levels of knowledge (P = 0.014), individuals younger and with lower knowledge showing lower attitude scores. Higher knowledge was related to a more positive attitude score for factor ‘certification substitutes’; and higher income and education level to a lower score for the ‘importance of certification’ factor. It is possible to stimulate both the development and promotion of restaurant certifications aimed at food safety.