Correct histopathologic diagnosis is essential for adequate treatment of soft tissue sarcomas. Due to the disorder's rarity, multitude of subgroups, sometimes varying histopathologic appearance, and occasionally inadequate biopsy specimens, diagnosis and grading are challenging. The records of 603 patients with soft tissue tumors of the extremities were reviewed concerning mismatches in primary and definite diagnoses relating to entity, evaluation of primary or recurrent tumor specimens, and the diagnosing pathology institution. For second opinions we referred to the Institute of Pathology of the Ruhr University at the Bergmannsheil Hospital in Bochum, Germany, and to the Pathology Institute of the University of Jena, also in Germany. Liposarcoma and malignant fibrous histiocytoma were the most often diagnosed subgroups at 24% and 22.6%, respectively. In the eight most frequent sarcoma types, malignant peripheral nerve sheath tumors and leiomyosarcoma had the highest rates of false primary diagnosis, 78.4% and 74.2% of cases, respectively. The diagnostic error ratio for nonspecialized pathologists in practice, community hospital pathologists, and academic medical centers was over 60%. For optimal treatment of soft tissue sarcomas, we suggest obtaining expert second opinion to ensure adequate surgical therapy and precise indications for radiation and chemotherapy.