Histological classification of soft tissue sarcomas can be made by light microscopy alone for those tumors with unique appearances, while a significant proportion of sarcomas require the implementation of electron microscopy or immunohistochemistry to obtain a final diagnostic classification. Immunostaining methods are particularly valuable in certain classes of sarcomas such as epithelioid sarcomas, malignant schwannomas, hemangiosarcomas, clear cell sarcomas, rhabdomyosarcomas, pleomorphic liposarcomas, leiomyosarcomas and synovial sarcomas through documentation of their cellular products. Immunohistochemistry is not a substitute for skilled interpretation of conventionally stained microscopic specimens; however, the availability of more specific determinants in the soft tissue neoplasms will expand the value of this approach in this area of diagnostic pathology.