This paper reports cross-national data concerning back or neck pain comorbidity with mental disorders. We assessed (a) the prevalence of chronic back/neck pain, (b) the prevalence of mental disorders among people with chronic back/neck pain, (c) which mental disorder had strongest associations with chronic back/neck pain, and (d) whether these associations are consistent across countries. Population surveys of community-dwelling adults were carried out in 17 countries in Europe, the Americas, the Middle East, Africa, Asia, and the South Pacific (N = 85,088). Mental disorders were assessed with the Composite International Diagnostic Interview, third version (CIDI 3.0): anxiety disorders (generalized anxiety disorder, panic disorder/agoraphobia, posttraumatic stress disorder, and social anxiety disorder), mood disorders (major depression and dysthymia), and alcohol abuse or dependence. Back/neck pain was ascertained by self-report. Between 10% and 42% reported chronic back/neck pain in the previous 12 months. After adjusting for age and sex, mental disorders were more common among persons with back/neck pain than among persons without. The pooled odds ratios were 2.3 [95% CI = 2.1–2.5] for mood disorders, 2.2 [95% CI = 2.1–2.4] for anxiety disorders, and 1.6 [95% CI = 1.4–1.9] for alcohol abuse/dependence in people with versus without chronic back/neck pain. Although prevalence rates of back/neck pain were generally lower than in previous reports, mental disorders were associated with chronic back/neck pain. The strength of association was stronger for mood and anxiety disorders than for alcohol abuse/dependence. The association of mental disorders with back/neck pain showed a consistent pattern across both developed and developing countries.