One of the main methods of modern cancer treatment is drug therapy but, it is found to be difficult to cure effectively. N-acetylcysteine (NAC), which is a membrane-permeable metal-binding compound, might have anti-cancer activity in the presence of different metals. In the present study synthesis of NAC with (Cu, Zn, Cd, Fe, Mg, Mn, Cr, Ni, Co, Se and Ag) by metals investigation and the formation of these complexes by IR, NMR. The effect of cytotoxicity of these complexes on Breast, Liver, Prostate and Ovary human cancer cell lines were evaluated. The best complexes were seen in cadmium N acetyl cysteine complex in breast, ovary, prostate and liver cell line.