Objective To investigate the clinical and imaging features of occult malignant tumors with acute cerebral infarction as the initial manifestation.Methods The patients who had acute cerebral infarction as the initial manifestation and were later diagnosed with malignant tumors in The First Affiliated Hospital of Anhui Medical University from January 2012 to May 2016 were enrolled. Their medical history, biochemical examination results, and imaging findings were analyzed.Results A total of 13 patients were enrolled, and there were 11 cases (84.6%) of digestive system or lung neoplasms and 11 cases (84.6%) of metastasis. The positive rate of tumor markers was 66.7%. Elevated D-dimer and fibrinogen degradation product (FDP) values were observed in 11 patients (91.7%) and 10 patients (100%), respectively. Of all patients, 11 (84.6%) had multiple brain infarctions, 76.9% had two or more circulations involved in cerebral infarction lesions, 61.5% had involvement of both anterior and posterior circulations, and 74.7% had small lesions.Conclusions In these patients, the primary tumor is mainly located in the digestive system or the lung with a high metastasis rate. There are significant increases in D-dimer and FDP values, which have a higher positive rate than tumor markers. Infarction lesions are more likely to occur in several circulations, especially the anterior and posterior circulations, and are mainly small lesions.