Background: Dysphagia is a frequent symptom in patients with acute stroke. It is associated with malnutrition, aspiration and mortality. The identification of early screening parameters for dysphagia promptly leading to a professional swallowing examination is therefore of utmost importance. This study aimed to detect early and easily assessable predictors of dysphagia in a large cohort of patients with acute ischemic stroke. Methods: Our analysis was based on data from a prospective in-hospital registry. Patients with ischemic stroke were included over the course of 3 years. Patients were scheduled to undergo a clinical swallowing investigation within the first 24 h after hospital admission. Step-wise multivariate logistic regression was used to identify independent predictors of dysphagia in general and of pneumonia in particular. Results: 1,646 patients with ischemic stroke were included. Stroke severity in terms of higher National Institute of Health Stroke Scale (NIHSS) values (p < 0.001), male gender (p = 0.006) and higher age (p < 0.001) independently predicted dysphagia. A receiver operating characteristics analysis revealed an NIHSS cut-off value of 4.5 for optimal differentiation between patients with and without dysphagia (sensitivity 0.77; specificity 0.77). Dysphagia (p < 0.001), male gender (p = 0.002), higher NIHSS scores (p < 0.001) and higher age (p = 0.002) were factors that were independently associated with pneumonia. The NIHSS cut-off value for differentiating between patients with and without pneumonia was 5.5 (sensitivity 0.91; specificity 0.67). Conclusions: Stroke severity in terms of NIHSS is a simple and reliable predictor of dysphagia. Patients with NIHSS values ≥5 should be quickly directed towards a professional swallowing examination. Dysphagia was confirmed to be a strong predictor of pneumonia.