Purpose: To identify trends in chronic obstructive pulmonary disease (COPD) diagnoses among active duty U.S. military personnel based on deployment history and whether International Classification of Disease, 9th edition (ICD-9) coding meet criteria for the diagnosis of COPD. Methods: A retrospective chart review using the electronic medical system was conducted for military personnel diagnosed with COPD based on ICD-9 codes for emphysema or chronic obstructive lung disease with at least three qualifying outpatient COPD-coded encounters. Clinical symptoms, smoking history, pulmonary function testing, and radiographs obtained during the diagnostic workup were reviewed. The established diagnosis of COPD was analyzed in relation to deployment. Results: A total of 371 patients were identified during the study period (2005–2009). Of these patients, 194 (52.3%) deployed, whereas 177 (47.7%) did not deploy to Southwest Asia since 2003. Thirty-four percent had no documented smoking history despite the diagnosis of COPD. Airway obstruction was identified by spirometry in only 67% of individuals diagnosed with COPD. No statistically significant differences in pulmonary function testing values were identified between those deployed and nondeployed individuals. Conclusion: Despite evidence of increased respiratory symptoms in deployed military personnel, the impact of deployment on increased diagnosis of COPD or severity of disease appears minimal.