Both theoretical considerations as well as empirical findings report mixed results on the relationship between sustainability disclosure and sustainability performance. Theoretical considerations are mainly based on legitimacy theory and voluntary disclosure theory. Due to shortcomings of previous studies with regard to the measurement of the main variables, our paper concentrates on new measurement approaches for sustainability disclosure and sustainability performance. Findings from a sample of 50 German and Swiss companies support our methodological approach. In particular, we find empirical evidence that legitimacy theory and voluntary disclosure theory likewise can explain certain aspects of sustainability reporting.