Since June 4, 2004, asthma diagnosed and symptomatic after the age of 12 years has been an exclusion criterion for military enlistment unless exempted via medical waiver. The Department of Defense determined that 13% of U.S. Army Medic visits in Iraq are for new-onset acute respiratory illness; case reports of veterans with asthma that began in Iraq and Afghanistan War zones have surfaced. This prompted our study to determine whether new asthma is diagnosed more frequently among Iraq/Afghanistan War troops versus stateside-based troops. Retrospective review of asthma diagnoses among computerized charts for military personnel discharged from active duty and examined between March 1, 2004 and May 1, 2007, at the Veterans Affairs Medical Center (VAMC), Northport, NY, classified soldiers by (1) deployment status-whether they were stationed in Iraq/Afghanistan for a 1-year tour of duty or stationed in the United States, and (2) VA diagnosis of asthma per International Classification of Disease codes. Associations between deployment and asthma statuses were evaluated/stratified by gender/age group. Eligibility criteria entailed (1) residence in Long Island, (2) aged 18-45 years, and (3) both U.S. military service and discharge dates between March 1, 2004 and May 1, 2007. Out of 6233 patients who served between 2004 and 2007 and were followed at the Northport VAMC, 290 new-onset/prevalent asthma cases were identified. Deployment to Iraq was associated with a significantly higher risk of asthma compared with stateside soldiers (6.6% versus 4.3%; with a crude odds ratio, 1.58; 95% CI, 1.18, 2.11). These associations persist when stratified by gender and age group. Deployment to Iraq and Afghanistan is associated with new-onset asthma. Etiologic studies, surveillance, incidence, epidemiology, and assessing response to therapy are recommended.