This study in 2004 and 2005 aimed to present the pattern of job stress among car manufacturing workers in one factory in the Islamic Republic of Iran, and to assess its relationship with occupational injuries. Data were collected from 608 male workers (508 at-risk general workers and 100 with injuries in the last year). Job stress was assessed by the Belkic occupational stress index. The prevalence of job stress was 21.3%. The main occupational stressors were time pressure (78.5%), mode of payment and evaluation (56.4%), and interaction with people and machines (41.3%). The risk of injury among those with job stress was significantly higher than those without job stress (OR = 2.0; 95% CI 1.20–3.30). Job stress was responsible for 11.9% of all occupational injuries in this group.