The aim of this study was to quantify the association between alcohol consumption and incidence of pneumonia and to examine possible pathways. This was done by a systematic review and meta-analyses on the dose-response relationship between alcohol consumption or alcohol-use disorders and the incidence of community-acquired pneumonia (CAP). The relative risk (RR) of CAP increased monotonically with increasing alcohol consumption. Individuals consuming 24, 60, and 120 g of pure alcohol daily demonstrated RRs for incident CAP of 1·12 (95% CI 1·02-1·23), 1·33 (95% CI 1·06-1·67) and 1·76 (95% CI 1·13-2·77), respectively, relative to non-drinkers. Clinically defined alcohol-use disorders were associated with an eightfold increased risk of CAP (RR 8·22, 95% CI 4·85-13·95). In conclusion, alcohol was found to be a risk factor for pneumonia with a clear statistical association, and a monotonic dose-response relationship.