['Mesenchymal chondrosarcoma (MSC) is a rare variant of chondrosarcoma. Because of the rarity of the disease, most studies only contain a small number of patients and thus the prognostic variables and role of adjuvant therapies remain controversial.', 'We therefore asked (1) what the overall and disease-free survival were for patients with this diagnosis at 5 and 10\xa0years; (2) whether there were significant prognostic factors associated with survival; and (3) whether use of adjuvant chemotherapy or radiotherapy was associated with survival in patients with MSC.', 'We retrospectively reviewed the cases of MSC diagnosed from 1979 to 2010 at one referral center. Forty-three cases were identified. Thirty-seven cases were analyzed for demographics, treatments, and outcomes. Thirty patients with localized disease were analyzed for prognostic factors. The minimum followup was 1\xa0month (mean, 6\xa0years; range, 1\xa0month to 17\xa0years). There were 17 females and 20 males. The mean age at diagnosis was 33\xa0years (range, 11-65\xa0years). Nineteen cases were skeletal and 18 cases were extraskeletal. Seventy-six percent of the tumors were located in the trunk.', 'Five- and 10-year overall survival was 51% and 37%, respectively. Five- and 10-year disease-free survival was 23% and 5%, respectively. Age (<\xa030\xa0years) and male sex were associated with poorer overall and disease-free survival in patients presenting with a localized tumor, respectively. Patients who did not receive radiotherapy were more likely to have a local recurrence. Adjuvant chemotherapy failed to show a significant association with overall, disease-free, metastasis-free, or local recurrence-free survival.'] Is radiation therapy associated with fewer recurrences in mesenchymal chondrosarcoma?