BACKGROUND: Alcohol problems can increase the risk of downward mobility within, or mobility out of, the workforce. The magnitude of this risk has been unclear, as has also been the question whether the risk is different for men and women, for different socio-economic classes, and for single-living compared with co-habiting people. METHODS: The study period was 1970-1980, when unemployment was low in Sweden. Information about socio-economic status from censuses was linked to hospitalization for alcoholism, alcohol psychosis and alcohol intoxication (AAA) over the period 1970-1975 in Stockholm County in persons aged 20-49 years in 1970 and gainfully employed in the same socio-economic category in both 1970 and 1975, and to general population data. The standardized rate ratio for mobility out of the workforce and for downward socio-economic mobility was calculated for those hospitalized with AAA. RESULTS: There was a statistically significant risk of mobility out of the workforce over the period 1976-1980 in both sexes and in all socio-economic groups. The relative risk was 6.63 for male skilled and semi-skilled manual workers and 9.52 for non-manual employees at medium and high level, while the corresponding figures were lower for women. The absolute risk of leaving the workforce was lowest in non-manual employees at medium and high level. The relative risk was reduced in persons who were co-habiting. CONCLUSIONS: Severe alcohol problems are powerful determinants of downward mobility within, or mobility out of, the workforce in both sexes and in all socio-economic categories.