The case report concerns a patient who, during a medical examination conducted to asses medical fitness to drive motor vehicles, concealed the truth about his health condition. Particular attention was paid to the discussion of the patient’s responsibility for the content of information provided in the interview. The article discusses criminal liability for making a false statement, for obtaining false certification by fraud and for using a document obtained by fraud. Attention was also drawn to the social obligation to denounce, which may also apply to physicians involved in medical certification. In case of medical examinations of drivers, every patient has a legal and moral obligation to provide the physician with truthful and complete information about his/her health, medications, past illnesses, and lifestyle. Providing false information or concealing important information can lead to an incorrect final diagnosis and, consequently, an incorrect decision, which can endanger the health and life of not only the driver but also other road users. Med Pr Work Health Saf. 2026;77(1)