89 cases of motor neuron disease (MND) were identified in Värmland County during the period 1970–1981. This amounts to an annual incidence rate of 2.6 per 100,000 population, sex- and age-adjusted to the USA population, 1.7. The average point prevalence was 8.5 per 100,000 population and the median duration of MND was 25 months. 95% of the MND cases in Värmland County were coded MND on their death certificates. MND was overrepresentated in persons performing heavy manual labor. A significantly higher mortality rate of MND in Värmland County was found compared to all Sweden (p