This study focuses on a large set of rehabilitation services used between 2004 and 2005 in one hospital district area in Finland. The rehabilitation system consists of several subsystems. This complex system is suggested to produce arbitrary rehabilitation services. Despite the criticisms against the system during decades, no attempts have been made to study the performance of the system as a whole. Register data from several subsystems were linked to study the use and characteristics of rehabilitation services and users. Data consisted of 10 153 persons. We analysed differences in rehabilitation service use between age and sex groups and municipalities. Totally, 5.4% of the population used rehabilitation services in the studied 2 years. Medical rehabilitation was the most common type, users' mean age was 52.6 years, and 52.2% were women. Remarkable differences were detected between municipalities in usage rates in all rehabilitation types. The size of the population in home municipality had a varying relation to utilization in different rehabilitation types. We found differences in the service use within age groups, sex or home municipality. This study cannot rule out the possibility that these differences indicated inequitable distribution of services or whether they are explained by different needs.