During the last 10 years, molecular testing of soft tissue tumors has become increasingly important, not only in the diagnostic approach of these lesions, but also regarding their prognosis and pathogenesis. A subset of soft tissue sarcomas bear chromosomal abnormalities including reciprocal translocations, deletions, mutations and amplifications, which turned out to be histotype specific. Beside their diagnostic value in sarcoma typing and subtyping (always in an appropriate clinical and histologic context), some of these abnormalities may also impact on treatment response and/or on prognosis. The aim of this review is to provide an overview of the most informative soft tissue sarcoma chromosomal abnormalities, and to give some clues about why and how we should detect them. Some sarcoma types (Ewing sarcoma, rhabdomyosarcomas, synovial sarcoma, well-differentiated/dedifferentiated and myxoid liposarcomas, gastrointestinal stromal tumors--GIST, malignant rhabdoid tumor) will be studied in more detail and the potential implication of these abnormalities in tumor genesis, growth, and maintenance will be briefly discussed.