Evident mental health needs among combat veterans after their return from combat have been described, whereas available data describing the mental health status of military personnel during deployment are few. Data were collected from personnel systematically selected from current combat regions participating in a rest and recuperation program in Doha, Qatar. Overall, 40620 troops completed a clinic screening form between October 2003 and January 2005. Rates of self-reported depression among troops in Afghanistan were lower than those of Iraq (32.3 vs 69.7 per 10000, P < .0001). Feelings of depression and self-harm were inversely correlated with rank (4-level ordinal grouping) (beta(Coef) = -.21, P = .0006; beta(Coef) = -0.49, P < .00001, respectively). Distinct temporal trends found in reported combat stress and monthly mortality rates were noted. These data support previous reports of higher mental health problems among troops in Iraq as compared with troops in Afghanistan and lower health care-seeking behavior overall. In an effort to remove barriers to care and minimize combat stress effects, it is critical to recognize mental health needs and initiate services during combat deployments.