Objective The present study sought to identify inequalities in cause-specific mortality across different occupational groups in Korea.

Methods The cohort included Korean workers enrolled in the national employment insurance programme between 1995 and 2000. Mortality was determined by matching death between 1995 and 2008 according to a nationwide registry of the Korea National Statistical Office. The cohort was divided into nine occupational groups according to the Korean Standard Occupational Classification (KSOC). Age-standardised mortality rates of each subcohort were calculated.

Results The highest age-standardised mortality rate was identified in KSOC 6 (agricultural, forestry and fishery workers; male (M): 563.0 per 100 000, female (F): 206.0 per 100 000), followed by KSOC 9 (elementary occupations; M: 499.0, F: 163.4) and KSOC 8 (plant, machine operators and assemblers; M: 380.3, F: 157.8). The lowest rate occurred in KSOC 2 (professionals and related workers; M: 209.1, F: 93.3). Differences in mortality rates between KSOC 2 and KSOC 9 (M: 289.9, F: 70.1) and the rate ratio of KSCO9 to KSCO2 (M: 2.39, F: 1.75) were higher in men. The most prominent mortality rate difference was observed in external causes of death (M: 96.9, F: 21.6) and liver disease in men (38.3 per 100 000). Mental disease showed the highest rate ratio (M: 6.31, F: 13.00).

Conclusions Substantial differences in mortality rates by occupation were identified. Main causes of death were injury, suicide and male liver disease. Development of policies to support occupations linked with a lower socioeconomic position should be prioritised.