I explore the usefulness of Martha Nussbaum's capabilities approach in regard to the UN Convention on the Rights of Persons with Disabilities (CRPD). The CRPD aims at empowering people with disabilities by granting them a number of civil and political, but also economic, social and cultural rights. Implementing the CRPD will clearly be politically challenging and also very expensive for states. Thus, questions might arise as to whether the requirements set in the CRPD can be justified from an ethical perspective. (...) I will first investigate if Nussbaum's capabilities approach provides support for the rights claimed in the CRPD. Second, I will investigate to what extent Nussbaum's capabilities approach is a useful tool to set priorities among rights in the course of the implementation of the convention. This is an urgent question because seen realistically, it will not be possible to realize all rights at once and thus some rights need to receive greater priority than others. I will argue that the capabilities approach can be regarded as supporting the rights specified in the CRPD, but that it proves unable to guide the implementation process due to an insufficient grounding of the capabilities. Employing the capabilities approach thus leads to only limited results. (shrink)