Background: Using a large cohort of western Canadian sawmill workers (n=28,794), the association between psychosocial work conditions and attempted and completed suicide was investigated. Methods: Records of attempted and completed suicide were accessed through a provincial hospital discharge registry to identify cases that were then matched using a nested case control method. Psychosocial work conditions were estimated by expert raters using the demand—control model. Univariate and multivariate conditional logistic regression was used to estimate the association between work conditions and suicide. Results: In multivariate models, controlling for sociodemographic (marital status, ethnicity) and occupational confounders (job mobility and duration), low psychological demand was associated with increased odds for completed suicide, and low social support was associated with increased odds for attempted suicides. Conclusions: This study indicates that workers with poor psychosocial working conditions may be at increased risk of both attempted and completed suicide.