The use of chemotherapy for cancer treatment is a successful modality. However, this treatment has its side effects, which limits its applicability.The aim of the present work is a comparative study of side effects of treatment of Cerastes cerastes snake venom and methotrexate on tumor progression in the primary site (thigh of the animal) and in secondary sites (metastasis) formation in the liver of mice. This will be achieved through histological, biochemical and tumor volume investigations on two main groups, (healthy animals and tumor bearing animals) to monitor side effects of the used methodologies on normal tissue and cancerous tissue.A total of 122 mice were used, divided into two groups, "A" and "B". Group A: normal control mice, was given saline 0.2 ml. Group B: tumor bearing mice, were subdivided into 3 subgroups: B1: received no treatment; B2: was interperitonealy injected with snake venom (0.75 μg/g); B3: was given 2.8 mg/kg methotrexate as standard chemotherapy. Histological examination of liver using hematoxylene and eosin (H& E), as well as blood analysis were performed. Results showed that exposure to ELF- MWs at resonance frequency 4.5 Hz, 2G was quite effective in limiting tumor growth and proliferation, with minimal effect on non- involved tissues. Its use proves to be much safe for treatment of primary tumor site and to secondary sites.