Background: The impact of stroke associated pneumonia (SAP) on stroke complications is not well understood; we aimed to study the association between SAP and adverse outcomes including in-hospital mortality, prolonged length of stay and the risk of developing common serious complications (sepsis, respiratory failure, and convulsions). Methods: We retrospectively analyzed data from a cohort of 610,668 stroke patients drawn from the Universal Coverage Health Security Scheme (a national insurance database) in Thailand which covers ∼80% of the Thai population. Patients were hospitalized between October 2004 and January 2013. Results: Pneumonia was present in 9.6 % (n = 58,586) of patients. Aspiration pneumonia was present in 6.2% (n = 38,060) a...