The purpose of this review is be based on recent studies to provide insight into what rare diseases are, what is their prevalence, and to point out the existing problem of insufficient knowledge and knowledge of the citizens as well as social services for people who suffer from them. Social sevices includes activities, measures and programs for the prevention, identification and resolution of problems and difficulties of individuals and families and to improve their quality of life in the community. Rare diseases affect a large number of people in the population, and it is believed that in Croatia 250,000 people suffer from those rare diseases. Because the disease is not only suffering for the patients, but also for their family members. The quality of life in patients can be improved by using orphan drugs intended to diagnose, prevention and treatment of rare diseases. Within the social, public, and even medical circles, there is very little knowledge of this type of diseases, which is why the medical and social protection is poorly organized and medications are expensive, and poorly investigated. The consequence is that in Croatia there are no registries of people with rare diseases and that only a small number of patients receive appropriate genetic information as part of genetic counseling.