Soft tissue sarcomas are malignant neoplasms derived from mesenchymal tissues. Their pathogenesis is poorly understood and there are few effective treatment options for advanced disease. In the past decade, gene expression profiling has been applied to sarcomas to facilitate understanding of sarcoma pathogenesis and to identify diagnostic, prognostic, and predictive markers. In this paper, we review this body of work and discuss how gene expression profiling has led to advancements in the understanding of sarcoma pathobiology, the identification of clinically useful biomarkers, and the refinement of sarcoma classification schemes. Lastly, we conclude with a discussion of strategies to further optimize the translation of gene expression data into a greater understanding of sarcoma pathogenesis and improved clinical outcomes for sarcoma patients.