Aims: Socioeconomic inequalities in both disability retirement and mortality are large. The aim of this study was to examine socioeconomic differences in cause-specific mortality after disability retirement due to different diseases. Methods: We used administrative register data from various sources linked together by Statistics Finland and included an 11% sample of the Finnish population between the years 1987 and 2007. The data also include an 80% oversample of the deceased during the follow-up. The study included men and women aged 30-64 years at baseline and those who turned 30 during the follow-up. We used Cox regression analysis to examine socioeconomic differences in mortality after disability retirement. Results: Socioeconomic differences in mortality after disability retirement were smaller than in the population in general. However, manual workers had a higher risk of mortality than upper non-manual employees after disability retirement due to mental disorders and cardiovascular diseases, and among men also diseases of the nervous system. After all-cause disability retirement, manual workers ran a higher risk of cardiovascular and alcohol-related death. However, among men who retired due to mental disorders or cardiovascular diseases, differences in social class were found for all causes of death examined. For women, an opposite socioeconomic gradient in mortality after disability retirement from neoplasms was found. Conclusions: The disability retirement process leads to smaller socioeconomic differences in mortality compared with those generally found in the population. This suggests that the disability retirement system is likely to accurately identify chronic health problems with regard to socioeconomic status.