The present study was designed to test the effect of S2-complex on head, neck, and bladder cancer patients by follow — up the changes in serum trace elements level (Se,Zn,Cu,Fe,Mg,Mn,and Cr) before and during treatment with S2-Complex, these results compared with head, neck and bladder cancer patients before and during chemotherapy treatment. The concentrations of trace elements (Zn, Cu, Fe, Mg, Mn, and Cr) for control group (65 patients) and normal group (50 person) were assessed using flame atomic absorption spectrophotometry, while selenium (Se) concentration was assessed using flameless atomic absorption spectrophotometry. The result in this study showed: 1. Significant difference in serum trace elements between normal and control group, and between control group and patients with head, neck, and bladder cancer after treatment with S2-complex and chemotherapy. 2. Significant difference in trace elements levels between S2 - complex treatment and chemotherapy for head, neck, and bladder cancer patients. 3. The age effect on trace elements levels.