There is much evidence to suggest that nature benefits human health. However, little is known about whether biodiversity is related to human health. In this study, we use a cross-sectional analysis to investigate the relationship between biodiversity and human health in Germany. As indicators for mental and physical health we use the Mental Health Component Scale (MCS) and Physical Health Component Scale (PCS) of the German Socio-Economic Panel (SOEP). For biodiversity, we use data on species diversity and abundance of two species groups: Plants and Birds. Our results show a significant positive association between plant and bird species richness and mental health across all model variants. In all our analyses we control for socio-economic factors and a wide range of natural features. These results show how important species diversity is for people’s mental health and well-being.