Malignant lymphoma in chest wall is a rare form of extranodal variety as occasionally localized tumor. The primary site is suggested from rib or soft tissue, but the incidence in rib is higher than soft tissue. The patient, a male, aged 32, noted a swelling and pain over the left lower posterior chest from 3 months prior to admission. Roentgenograms revealed bony destruction in left 9, & 19th ribs posteriorly and associated chest wall mass which was ill defined uncleared margination. Under diagnosis of malignant tumor, the operation was performed and the tumor mass resected widely with en bloc technique than the fascia lata was grafted at chest wall defect. The histology of specimen was disclosed as malignant lymphoma, non-Hodgkin`s diffuse lymphocytic poorly differentiated form. The radio-and chemotherapy were combined post-operatively and the complete remission *is acquired.[KTCS 1983;1:176-182]