Background: Sinonasal teratocarcinosarcoma (SNTCS) is a very rare aggressive neoplasm of the sinonasal tract and affects older individuals. The tumor accounts for <1% of all sinonasal neoplasm and shows a striking male predominance. The admixture of epithelial, mesenchymal, and primitive neuroepithelial elements is essential for the diagnosis of this tumor. However, the morphological differential diagnosis of SNTCS is wide and can lead to potential diagnostic error if any one of the three elements predominates in a biopsy. Case description: We report three cases of SNTCS from a single center. All three patients were middle-aged adults, including one male and two female patients. The age range was between 42 and 46 years. All of the three patients presented with nasal obstruction, pain, and nasal bleeding. The imaging study revealed a direct intracranial extension of the tumor in one of the patients. Two patients underwent frontal craniotomy, and the third patient underwent transnasal decompression of the tumor. On light microscopic examination, all three cases revealed similar morphology. The tumor tissue was composed of three distinct components, including malignant epithelial, mesenchymal, and primitive neuroepithelial elements. Immunohistochemistry (IHC) showed strong pan-cytokeratin (AE1/AE3) positivity in the epithelial component. The mesenchymal component showed varied differentiation, including osseous and rhabdomyoblastic differentiation. The primitive neuroepithelial element showed positivity for cluster of differentiation 99 (CD99) and synaptophysin IHC. Conclusion: Sinonasal teratocarcinosarcoma (SNTCS) is often underdiagnosed because of the rarity of this tumor and its histomorphological overlap with a wide range of sinonasal malignancies. A careful morphological assessment of the biopsy sample and a battery of ancillary investigations, including IHC, confirm the diagnosis.