Health professionals are exposed to various occupational risks, with the greatest impact from biological hazards due to direct contact with potentially contaminated organic materials. Besides adopting universal biosafety measures, adequate immunization coverage must be achieved in this context, with educational initiatives playing a crucial role in the process. This was a cross-sectional observational study of undergraduates (n = 136) at the Medical School of the Federal University in Juiz de Fora to assess their immunization status and biological risk perceptions. Eighty-nine students (65.4%) reported a complete vaccination schedule. Ninety-seven (71.3%) had received full immunization against hepatitis B and 99 (72.8%) against tetanus. Eighty-six (63.2%) reported having received immunization advice during the course. Seventy-three (53.7%) had already been exposed to potentially contaminated material during their academic activities, and 97 (71.3%) used personal protective equipment (PPE) in these contexts. We identified missed immunization doses against hepatitis B and tetanus, a situation that exposes medical students to unnecessary risks. Immunization advice was insufficient. The significant rate of exposure to biological hazards and the unsatisfactory use of PPE call for greater attention to accident prevention.