Myxoinflammatory fibroblastic sarcoma (MIFS) is a recently defined rare tumor. It is mainly found in the upper and lower extremities of adults. Due to its high local recurrence rate and low metastatic rate, it is classified as a low grade-malignancy. Accurate diagnosis and early, wide excision are important for prognosis. Herein, we report a case of MIFS in a 35-year-old male patient that presented in an unusual location, the left chest wall. To our knowledge, this is the first reported case of MIFS in Korea and the second case to be reported within the global scientific literature involving the chest wall.