Sexual health is an important part of an individual’s overall health profile. However, for people with a severe mental illness (SMI), maintaining optimal sexual health can be a challenge. Mental health nurses have an important role in addressing patients’ sexual health needs. Nurses’ beliefs, outlooks and resulting attitudes towards a patient’s sexuality appear to be one of the barriers to promoting sexual health for people experiencing SMI. This article examines the issue of sexual health for patients with SMI and the factors affecting the promotion of optimal sexual health in this patient group.