According to Western canonists, husband and wife had a debt towards one another: they were obliged to render sexual intercourse on demand. This article looks at the differences and similarities of the ‘marital debt’ in Byzantium and the West in order to evaluate whether this concept can be applied to Byzantine couples. It argues that, contrary to the West, in Byzantium there was no fixed linguistic terminology or sophisticated rules to describe a sexual obligation between spouses. Ultimately, there was also less need for one as sexual intercourse within marriage was not considered sinful and needed no justification.