Background: Stroke-associated pneumonia often negatively influences the prognosis of stroke patients. The aims of this study were to determine the frequency of pneumonia and to investigate the correlation between pneumonia and prognosis in stroke patients receiving intravenous thrombolysis with recombinant tissue plasminogen activator (IV thrombolysis). Methods: Between 2008 and 2013, 538 consecutive stroke patients (mean age, 72 +/- 13 years; 50.4% women) receiving IV thrombolysis at the Department of Neurology, University of Lubeck, were investigated. Results: Pneumonia occurred among 122 patients (23%; 95% confidence interval [CI], 19.1-26.2). Pneumonia patients were older (76 versus 71 years; P < .001), more severely affected at admission (National Institutes of Health Stroke Scale [NIHSS] score, 13 versus 9; P < .001), and more likely to have atrial fibrillation (54% versus 42%; P = .02) than patients without pneumonia. They had also a longer hospitalization (15 versus 10 days; P < .001). Using logistic regression analysis, the occurrence of pneumonia was associated with male sex (odds ratio [OR], 1.9; 95% CI, 1.2-3.1; P = .006), neurologic deficit severity (NIHSS score >= 10; OR, 4.4; 95% CI, 2.5-7.4; P < .0019), previous stroke (OR, 1.5; 95% CI, 1.0-2.2; P = .06), and occurrence of symptomatic intracerebral hemorrhage (OR, 1.6; 95% CI, 1.0-3.2; P = .048). Mortality rates (in-hospital mortality [18.9% versus 7.0; P < .0019]; 3-month mortality [34.3% versus 10.6%; P < .001], and 12-month mortality [53.6% versus 19.6%; P < .001]) were higher in pneumonia patients than those without. A favorable outcome (modified Rankin Scale score <= 2) was more likely in patients without pneumonia than those with pneumonia (42% versus 7%; P < .001). Conclusion: Pneumonia was correlated with increased age, male sex, neurologic deficit severity, and a less favorable prognosis.