Purpose To investigate return to work (RTW) in employees sick-listed with mental disorders classified according to the International Classification of Diseases (ICD). Methods Sickness absences (SA) medically certified as emotional disturbance (ICD-10 R45) or mental and behavioral disorders (ICD-10 F00-F99) were retrieved from an occupational health service register. RTW was associated with age, gender, and socioeconomic position (SEP) by parametric survival analysis. Results Emotional, neurotic, somatoform, stress-related, and mood disorders encompassed 94 % of all mental SA. Employees with emotional disturbance had the highest RTW rates: after 1 year 95 % had resumed work and after 2 years 98 % compared to 89 and 96 % of employees with neurotic, somatoform and stress-related disorders, and 70 and 86 % of employees with mood disorders. The probability of RTW decreased after 1 month of SA due to emotional disturbance, 2 months of SA with neurotic, somatoform and stress-related disorders, and 3 months of SA with mood disorders. Women resumed their work later than men. Young employees presenting with emotional disturbance, neurotic, somatoform, and stress-related disorders had earlier RTW than older employees and low-SEP employees had earlier RTW than high-SEP employees. Conclusions RTW rates and probabilities differed across categories of mental disorders. Age and SEP were associated with RTW of employees with emotional, neurotic, somatoform, and stress-related disorders, but not with RTW of employees experiencing mood disorders. To maximize the likelihood of RTW, a focus on RTW is important in the first months after reporting sick with mental disorders.