After Lithuania joined the European Union, the Regulation (EC) No. 141/2000 on orphan medicinal products and Commission Regulation (EC) No. 847/2000 came into force as part of national legislation. Member States must adopt specific measures to increase knowledge on rare diseases and to improve their detection, diagnosis, and treatment. The aim of this article was to present and to assess the current legal situation on orphan patients and their treatment in Lithuania, to identify legislation gaps, and to propose some ideas how to facilitate the solution of the existing problems in this field. For this purpose, European Union and Lithuanian legal documents on rare medicinal products are examined using a comparative method. With reference to inventory of Member States' incentives for rare diseases in national level, the most important issues, which orphan patients face to in Lithuania, are singled out. In Lithuania, the situation of orphan patients in terms of protection of patient rights is insufficiently determined. The access to effective health care services or approved therapies in some cases is restricted. Working relationships between genetic services and various clinical specialists as well as with those in primary care are not legally determined; the number of clinical trials aimed at orphan medicinal products is low. These results suggest a need for awareness raising among Lithuanian Government, health care specialists, patient organizations about the importance to improve practical implementation of European Union legislation and progressive experience of some European countries in this field.