As hemorrhagic transformation (HTr) is a frequent complication and can worsen the outcome of acute ischemic stroke, our aim was to assess the risk factors of HTr. Using the database of our neuropathological laboratory, 245 consecutive acute ischemic stroke patients were analyzed. An exploratory logistic regression procedure was carried out to find the best multiple model identifying the factors associated with HTr. The autopsy revealed ischemic infarct in 175 (71%) and ischemic infarct with HTr in 70 (29%) patients. Mean age was 71.5 ± 11.4 years (mean ± SD) and 74.8 ± 10.2 years (mean ± SD), respectively. The multiple model confirmed age in case of embolic stroke, and diabetes mellitus and infarct size as independent risk factors of HTr. It seems that not serum glucose level but diabetes mellitus in the case history is an independent predictor of HTr.