This paper deals with differences in health and health behaviour between those who are insured in the German Statutory Sickness Funds (GKV) and those who are privately insured (PKV). This topic has been largely ignored in German Public Health research. The analyses are based on data from a large survey in Germany conducted in 1998 and including 6822 adults. The multivariate analyses have been performed with OLS and logistic regression, separately for men and women and controlling for age, educational level, income and region. The most important result is that PKV-insured men have fewer diseases and feel more healthy than GKV-insured men. For women, though, no significant association could be found between health and type of health insurance. The interpretation of these results is mainly based on the "selection hypothesis", stating that healthier persons are more likely to be insured in the PKV than in the GKV. This would imply that the "causation hypothesis" (stating that being privately insured has a positive effect on health) is less important. Taking into account the current discussion on the balance between GKV and PKV, it is believed that future research should focus more on these topics.