BACKGROUND Garlic is known as a medicinal herb with broad therapeutic properties ranging from antibacterial to anticancer and even anticoagulant. OBJECTIVE Current study was designed to evaluate antitumor effects of aged garlic extract (AGE) on fibrosarcoma tumor in BALB/c mice. METHODS WEHI-164 fibrosarcoma cells were implanted subcutaneously on day zero into right flank of 40 BALB/c mice aged eight weeks. Mice were randomly categorized in two separate groups: 1(st) received AGE (100 mg/kg, intraperitoneally), 2(nd) group as control received phosphate buffered saline, (PBS). Treatments were done three times per week. Tumor growth was measured and morbidity was recorded. Subpopulations of CD4+/CD8+ T cells were determined using flow cytometry. WEHI-164 cell specific cytotoxicity of splenocytes and in vitro production of gamma-interferon, (IFN-γ) and Interleukin-4, (IL-4) cytokines were measured. RESULTS The mice received AGE had significantly longer survival time compared to control mice. The inhibitory effect on tumor growth was seen in AGE treated mice. The CD4+/CD8+ ratio and in vitro IFN-γ production of splenocytes were significantly increased in AGE group. CONCLUSIONS Administration of AGE resulted in improved immune responses against experimentally implanted fibrosarcoma tumors in BALB/c mice. AGE showed significant effects on inhibition of tumor growth and longevity of survival times.