Background: Military deployment to combat zones puts military personnel to a number of physical and mental challenges that may adversely affect mental health. Until now, few studies have been performed in Europe on mental health utilization after military deployment. Objective: We compared the incidence of mental health consultations with the Military Mental Health Service (MMHS) of military deployed to Afghanistan to that of non-deployed military personnel. Method: We assessed utilization of the MMHS by the full cohort of the Netherlands Armed Forces enlisted between 2008 and 2010 through linkage of mental health and human resource information systems. Results: The total population consisted of 50,508 military (18,233 deployed, 32,275 non-deployed), who accounted for 1,906 new consultations with the MMHS. The follow-up was limited to the first 2 years following deployment. We observed higher mental health care utilization in deployed vs. non-deployed military personnel; hazard ratio (HR), adjusted for sex, military branch and time in service, 1.84 [95% CI 1.61–2.11] in the first and 1.28 [1.09–1.49] in the second year after deployment. An increased risk of adjustment disorders (HR 2.59 [2.02–3.32] and 1.74 [1.30–2.32]) and of anxiety disorders (2.22 [1.52–3.25] and 2.28 [1.50–3.45]) including posttraumatic stress disorder (5.15 [2.55–10.40] and 5.28 [2.42–11.50]), but not of mood disorders (1.33 [0.90–1.97] and 1.11 [0.68–1.82]), was observed in deployed personnel in the first- and second-year post-deployment, respectively. Military personnel deployed in a unit with a higher risk of confrontation with potentially traumatic events had a higher HR (2.13 [1.84–2.47] and 1.40 [1.18–1.67]). Conclusions: Though absolute risk was low, in the first and second year following deployment to Afghanistan there was an 80 and 30% higher risk for mental health problems resulting in a consultation with the Dutch MMHS compared to military never deployed to Afghanistan. These observations underscore the need for an adequate ...