Objectives: To determine the effects of work-related psychosocial and organizational factors on headache. Methods: A random cohort from the Norwegian general population (aged 18 to 66 years) had been observed for 3 years. Eligible respondents answered a question about headache, and were engaged in paid employment during the reference weeks in 2006 and 2009, or were temporarily absent from such work (N = 3325). Results: In the fully adjusted model, the main risk factors were high role conflict (highest odds ratio [OR] = 2.86; 95% confidence interval [CI] = 1.49 to 5.48), low social climate (highest OR = 2.21; 95% CI = 1.09 to 4.49), bullying/harassment (OR = 3.94; 95% CI = 1.36 to 11.42), and downsizing (OR = 2.38; 95% = 1.20 to 4.71). Conclusions: Role conflict, low social climate, and bullying/harassment were the main predictors of headaches. These factors should be considered to prevent headaches at work.