Many people are diagnosed with MS at a time when they are, or may be about to become, sexually active in their relationships. The issues associated with how best to manage sexual activity and MS have in the past often proved difficult to discuss with others. However, increasingly, both doctors and other health professionals concerned with MS are aware of the importance of such issues and are able to offer helpful support and advice. In this chapter, we address some of the common worries that men and women with MS, and their partners, may have. Multiple sclerosis – the ‘at your fingertips’ guide contains more information on this subject. We start with a discussion about problems with erections, common issues affecting men with MS, and their sexual relationships.