Aim Hospital‐associated dysphagia, characterized by deconditioning of swallowing as a result of hospitalization, is sometimes observed in patients with aspiration pneumonia (AP). Cognitive impairment is known as a negative factor in dysphagia rehabilitation. The present study aimed to examine the association between cognitive impairment and hospital‐associated dysphagia in patients with AP receiving dysphagia rehabilitation. Methods A retrospective observational study was carried out in an acute geriatric hospital. A total of 249 AP patients receiving multidisciplinary individualized dysphagia rehabilitation were included. Patients were divided into four groups according to their Mini‐Mental State Examination scores. The Functional Oral Intake Scale (FOIS) was used to assess swallowing ability, and hospital‐associated dysphagia was defined as a FOIS decline of ≥1 or ≥2 levels. Body mass index and Barthel Index were obtained to assess nutritional status and activities of daily living. Results The mean age was 85.6 ± 7.3 years, and 47% were men. Frequencies of hospital‐associated dysphagia observed in lowest to highest Mini‐Mental State Examination groups were 43.0%, 36.2%, 47.4% and 27.3% (P = 0.133), and 13.9%, 20.7%, 17.5% and 5.5% (P = 0.117) based on FOIS decline ≥1 or ≥2 levels, respectively. Multivariable regression model showed that the Mini‐Mental State Examination score was not an independent determinant of FOIS at discharge (beta = 0.063, P = 0.378) after adjusting for age, sex, body mass index, Barthel Index, pneumonia severity, speech‐language pathologist intervention, comorbidities, length of hospital stay and premorbid FOIS. Conclusions The severity of cognitive impairment has no impact on hospital‐associated dysphagia in AP patients receiving dysphagia rehabilitation. A future interventional study will be expected to further validate our findings. Geriatr Gerontol Int 2017; ••: ••–••.