Mortality figures for Parkinson's disease in Canada from 1979 to 1986 were examined by province and by sex. As seen in other studies, Parkinson's disease showed a statistically significantly higher prevalence in males than in females (p < 0.01). An uneven distribution across provinces was found when mortality rates were compared by males and when males and females were grouped together. Females did not show a significant variation across provinces. Five provinces showed a higher incidence of Parkinson's disease among males than in females (p < 0.05), whereas the other provinces showed no difference. British Columbia and Manitoba showed the highest rates for males as well as the highest rates when males and females were grouped together. The uneven geographic distribution of Parkinson's disease offers support for the possible involvement of environmental factors in the etiology of some forms of idiopathic Parkinson's disease. Suggestions for further research are outlined.