ABSTRACT Objective: To identify the perception of medical students and physicians on the importance of vaccination and the risks of vaccine refusal. Methods: Cross-sectional study with application of questionnaires about vaccines, vaccine refusal and its repercussions on public and individual health. A sample of 92 subjects was selected from a private medical school: group 1 (53 students from first to fourth grades) and group 2 (39 physicians). Data collected were tabulated in the Microsoft Excel Program and analyzed by Fisher’s exact test. Results: Both groups considered the National Immunization Program reliable and recognized the importance of vaccines, but 64.2% of students and 38.5% of physicians are unaware of the vaccine-preventable infectious diseases in the basic immunization schedule. Most of the interviewees had a personal vaccine registry, but not all had received the 2015 influenza vaccine. Both groups had known people who refused vaccines for themselves or for their children (respectively, 54.7 and 43.3% of students and 59.0 and 41.0% of physicians). The total of 48.7% of physicians had already assisted vaccine refusers. Appointed causes of vaccine refusal were: fear of adverse events, philosophical and religious reasons and lack of knowledge about severity and frequency of diseases. Ethical aspects of vaccine refusal and legal possibilities of vaccine requirements for children are not consensus. Conclusions: Medical students and doctors are not adequately vaccinated and have queries about the vaccination schedule, vaccine safety and vaccine refusal. Improving these professionals’ knowledge is an important strategy to maintain vaccine coverage and address vaccine refusal ethically.