A scoping review of the existing evidence on prognostic factors of sickness absence (SA) and return to work (RTW) among workers with a common mental disorder (CMD) will be conducted in a systematic way following all "a priori" methodological steps as planed in this study protocol. A best evidence synthesis of known prognostic factors for (recurrent) SA and RTW in workers with CMD, classified consistent with the domains of the International Classification of Functioning, Disability and Health will be presented in the scoping review aiming the designing of more effective interventions for preventing SA and promoting RTW.