Aims and Background: Gliosarcoma is an uncommon primary malignant tumor of the central nervous system. Gliosarcoma is a variant of glioblastoma, which includes glial and mesenchymal differentiation sites and has biphasic tissue patterns. They form up to 2% of all glioblastomas, and are similar to the glioblastoma in terms of prognosis. Four patients presenting with gliosarcoma were reviewed and are discussed herein with respect to their clinical and histopathological characteristics. The diagnosis was suspected based on radiological findings and was confirmed by histological examination. Methods: The tumors were diagnosed with neurological examination and neuroimaging methods. There were 4 patients (3 males and 1 female; age range: 33 to 36 years). All the tumors were located in the supratentorial region. All the patients underwent surgery with craniotomy and three of them received post-surgical radiotherapy (RT). Results: Despite the surgical resection and RT, one patient died in the early stage. Recurrences were seen in the follow-up exams between 9-13 months. All of the patients died in the follow-up period. Pathological diagnosis of the patients was gliosarcoma. Biphasic tissue pattern including gliomatosis and sarcomatosis sites, which is a typical characteristic of gliosarcoma, was histopathologically detected. Conclusions: Gliosarcoma is also seen clinically with aggressive course and poor prognosis. These tumors are accepted as grade IV according to the World Health Organization classification and the recurrence rates are high. Surgical resection and RT are the most efficient treatment procedures as in all glial tumors, with poor prognosis.