Solitary fibrous tumor (SFT), is a rare mesenchymal spindle cell tumor and its biological behavior is hard to predict. There is no characteristic clinical manifestation and morphologic features showed broad spectrum, so often diagnosed as other spindle cell mesenchymal tumor, benign or Malignant. In most cases, immunohistochemistry staining (IHC) is needed to diagnose SFT. The aim of this retrospective study is to see demographic data, histopathological features and the importance of IHC staining diagnosis of SFT. Secondary data was obtained from Department of Anatomical Pathology, Faculty of Medicine, Universitas Indonesia in 2010-2016. There were 35 samples included in this review; most are male (20 cases) aged <55 years old. Thirty one cases were in the extrapleural site and most of the tumor is less than 5 cm in diameter. There are 20 cases of cellular SFT while the other is fibrous SFT. Commonly, cellular SFT shows moderate cellularity and pleiomorphism. Fibrous SFT are well circumscribed and without necrosis. There are only 3 cases of Malignant SFT which is located in intra-abdominal and orbit. Generally, SFT is benign, small, and well circumscribed. Most of the cases are cellular than fibrous; mild to moderate nuclear pleiomorphism, mitotic activity low, and without necrotic. Features of Malignant SFT are hypercellularity, moderate to high nuclear pleiomorphism, mitotic >4/10 high power field (HPF) and necrosis. Most SFT are benign, some may recurrence and metastasize.