Abstract: One of the well-known cellular defenses after exposure to cytotoxic agents is the glutathione (GSH) related mechanisms. Resistant to cisplatin (DP) chemotherapy has been strongly correlated to GSH-mediated mechanisms in many articles. In this study, we have evaluated the effects of cisplatin on the cellular total GSH level in different tumor and normal cell lines. Five different cell lines of human hepatic carcinoma (HePG2), human lung adenocarcinoma (A549), human ovarian carcinoma (SKOV3), dog kidney (LLCPK1), Chinese Hamster Ovary (CHO) and Human gingival fibroblast (GHF1) cell lines were exposed to their respected IC50 concentrations of cisplatin for two hours. Cisplatin cytotoxicity was measured using clonogenic assay and the total cellular GSH level was analyzed using a photometrical assay. The results showed that cisplatin had different degrees of cytotoxicities on different cell lines as shown by IC50 values; 0.87± 0.07 for HepG2, 3.27±0.35 for A549, 0.99±0.08 for SKOV3, 5.50±0.35 for LLCPK1, 5.50±0.21 for CHO and 1.60±0.21 for GHF1 cell lines. GSH level after exposure to cisplatin (GSH-DP) were also different for different cell lines compare to their controls (GSH-C); 85.33±8 for HepG2, 637.00±81 for A549, 2691.00±416 for SKOV3, 1388.30±261 for LLCPK1, 412.60±32 for CHO and 783.24±30 for GHF1 cell. It is shown that compare to the matched controls, the cellular GSH level increased in LLCPK1, A549, SKOV3 and GHF1 cell lines, but decreased in CHO and HepG2 cell lines. The highest significant variation of GSH in cancer cell line was belonging to SKOV3 and in normal cell lines to LLCPK1, after treated with cisplatin. It is concluded that the total GSH variation after exposure to cisplatin is different for different cell lines. We were not able to correlate between the level of resistance to cisplatin (based on the IC50 levels) and GSH level or variations in this study. It might indicate that in spite of many publications so far, the GSH is neither the unique, nor the most important mechanism of resistance to cisplatin in these cell lines. Internal and Eternal GSH level in Studied cell lines will be changed in several ways when contaminated with different concentration of vitamins (for examples, Vit C, Vit E and Vit C+E) and observed that variation was more prominent in cancer cell line.