Abstract: Exposure to toxins-such as heavy metals and air pollution-can result in poor health and wellbeing. Recent scientific and media attention has highlighted negative health outcomes associated with toxic exposures for U.S. military personnel deployed overseas. Despite established health risks, less empirical work has examined whether deployment-related toxic exposures are associated with declines in mental and physical health after leaving military service, particularly among the most recent cohort of veterans deployed after September 11, 2001. Using data from 659 U.S. veterans in the VISN 6 MIRECC Post-Deployment Mental Health Study, we tested whether self-reported toxic exposures were associated with poorer mental and physical health. At baseline, veterans who reported more toxic exposures also reported more mental health, β = 0.14, 95% CI [0.04, 0.23], p = 0.004, and physical health symptoms, β = 0.21, 95% CI [0.11, 0.30], p < 0.001. Over the next ten years, veterans reporting more toxic exposures also had greater increases in mental health symptoms, β = 0.23, 95% CI [0.15, 0.31], p < 0.001, physical health symptoms, β = 0.22, 95% CI [0.14, 0.30], p < 0.001, and chronic disease diagnoses, β = 0.15, 95% CI [0.07, 0.23], p < 0.001. These associations accounted for demographic and military covariates, including combat exposure. Our findings suggest that toxic exposures are associated with worsening mental and physical health after military service, and this recent cohort of veterans will have increased need for mental health and medical care as they age into midlife and older age.