Introduction Smoking is a major risk factor for chronic obstructive pulmonary disease (COPD). Serving military personnel have previously been shown to be more likely to smoke, and to smoke more heavily, than civilians, but there is no clear consensus as to whether in later life, as veterans, they experience a higher prevalence and mortality from COPD than do non-veterans. We examined the risk of COPD in Scottish veterans and assessed the impact of changes in military smoking.

Methods Retrospective 30-year cohort study of 56 205 veterans born 1945–1985, and 172 741 people with no record of military service, matched for age, sex and area of residence, using Cox proportional hazard models to examine the association between veteran status, birth cohort, length of service and risk of COPD resulting in hospitalisation or death.

Results There were 1966 (3.52%) cases of COPD meeting the definition in veterans, compared with 5434 (3.19%) in non-veterans. The difference was statistically significant (p=0.001) in the unadjusted model although it became non-significant after adjusting for deprivation. The highest risk was seen in the oldest (1945–1949) birth cohort and in veterans with the shortest service (Early Service Leavers). The risk was significantly reduced in veterans born from 1960, and in those with over 12 years' service.

Conclusions Our findings are consistent with falling rates of military smoking since the 1960s, and with the reduction in smoking with longer service. The oldest veterans, and those with the shortest service, are least likely to have benefited from this, as reflected in their higher risk for COPD.