The ability to accurately define the prognosis for patients with soft tissue sarcoma is a continuing challenge. Classically, this has been accomplished through assessments of tumor size, histologic grade, location, and the presence of nodal or distant metastases. These criteria are the basis of the currently utilized American Joint Commission on Cancer (AJCC) staging system. However, several other markers have been identified which have prognostic value. These newer markers are useful additions to the AJCC system. Such markers may not only improve our ability to prognosticate at diagnosis, but may also prove useful in selecting high-risk soft tissue sarcoma patients who could benefit from adjuvant therapy. This review will focus upon prognostic factors for patients with soft tissue sarcomas (STS). First, the components of the current AJCC staging system will be discussed; second, a summary of clinical prognostic factors which are not part of the staging system; and third, a discussion of newer and potential prognostic factors for STS patients.