Objectives: This study aims to investigate the diagnostic and prognostic role of mean platelet volume (MPV) and MPV/platelet (PLT) ratio in the most common soft tissue sarcomas.Patients and methods: We retrospectively investigated 131 patients (76 males, 55 females; mean age: 51.8±17.1; range, 18 to 87 years) with soft-tissue sarcomas between January 2011 and January 2019. Demographic features, MPV, PLT counts, mortality, and recurrence records of the patients were obtained from archives. A total of 165 healthy volunteers (101 males, 64 females; mean age 52.9±4.1; range, 18 to 60 years) who applied to the outpatient clinic in 2019 and had routine blood control without any additional disease formed the control group.Results: A total of 55 patients were diagnosed with liposarcoma and 76 with pleomorphic sarcoma. Of the tumors, 77.1% were located in the lower limbs. Lesions were mostly localized on the thigh 48.8% (n=64). Recurrence occurred in 28.2% of the patients. A total of 25 (19.1%) patients were exitus. The mean follow-up period of the patients was 34.4±19.1 (range, 9 to 112) months. The mean PLT value of the patient group was significantly higher than the control group. The median MPV and MPV/PLT ratio were statistically significantly lower in the patient group than in the control group. The MPV and MPV/PLT ratio were not associated with mortality and recurrence.Conclusion: As a result, MPV and MPV/PLT ratio can be used as a diagnostic support parameter in soft tissue sarcomas, but have no prognostic value.