Most existing health-related quality of life research concerns the impact of disease on patients. However, in several medical specialties including dermatology, oncology, and physical and mental disability, studies have been carried out investigating the impact of disease on the lives of families of patients. The aim of this paper is to review the literature which relates to the impact of disease on family members of patients. The OVIDSP Medline was selected as the primary database, Searches were limited to sources published in English. 158 papers were identified for review. The definition of "family" varied across the literature, and a broad definition was accepted in this review. This review shows that a wide variety of aspects of family members' lives can be affected, including emotional, financial, family relationships, education and work, leisure time, and social activities. Many of these themes are linked to one another, with themes including financial impact and social impact being linked to emotional impact. Some positive aspects were also identified from the literature, including family relationships growing stronger. Several instruments exist to measure the impact of illness on the family, and most are disease or specialty- specific. The impact of disease on families of patients is often unrecognised and underestimated. Taking into account the quality of life of families as well as patients can offer the clinician a unique insight into issues such as family relationships and the effect of treatment decisions on the patient's close social group of partner and family.