Objective: to assess the culture of safety in three public hospitals.Method: transversal study undertaken in three Brazilian public hospitals, with health professionals through applying the Safety Attitudes Questionnaire (SAQ). Scores greater than or equal to 75 were considered positive.Results: a total of 573 professionals participated in the study, including nurse technicians and auxiliary nurses 292 (51%), nurses 105 (18.3%), physicians 59 (10.3%), and other professionals 117 (20.4%). The mean of the SAQ varied between 65 and 69 in the three hospitals. Among the domains, however, 'Job satisfaction' presented a higher score, and the opposite was observed for the domain 'Perceptions of management'. The outsourced professionals presented a better perception of the culture of safety than did the statutory professionals. The professionals with higher education presented a better perception of the stressing factors than did the professionals educated to senior high school level.Conclusion: the level of the culture of safety found is below the ideal. The managerial actions are considered the main contributing factor to the culture's weakness; however, the professionals demonstrated themselves to be satisfied with the work.