Infectious diseases are still a worldwide health problem, and hence physicians are responsible for providing the population with sufficient vaccinations. Until now, however, comprehensive studies on vaccination behaviour in German medical/dental students, the future physicians/dentists, are lacking. The study analysed vaccinations of medical/dental students against tetanus, diphtheria, poliomyelitis, hepatitis A + B and tried to find possible influences on the vaccination behaviour. 126 medical and 99 dental students participated by working on an anonymous questionnaire related to sociodemographic data, smoking/drinking habits, drug abuse and vaccinations. The response rate was between 76 and 85%. Altogether, the investigated students were not sufficiently vaccinated. Nevertheless, they were better vaccinated than a normal reference sample. Except for a significantly better immunisation against hepatitis B in dental students, no differences between medical and dental students were found. In comparison to male students, female students presented better immunisation. On the other hand, students from the former West Germany, smoking students and students who are taking illegal drugs, were more insufficiently immunised than the other students. To optimise vaccinations in future physicians and dentists, medical/dental education should focus more on infectious diseases and knowledge about vaccinations. This would help to protect future physicians and dentists against preventable infectious diseases. Additionally, they are better skilled to prevent infectious diseases by providing the population with information and vaccinations.