In this study, the adsorption of Flutamide (FLT) anticancer drug on the Zn doped single-walled carbon nanotube (5, 5) (SWCNT-Zn (5, 5)) has been investigated. This study has been performed in the gaseous phase and in water and ethanol solvents phases, in the basis and excited states, using density functional theory (DFT) and molecular orbitals (MO) calculation methods. DFT calculations performed at B3LYP quantum chemical level abs at 6-311G (d, p) basis set. Firstly, the structure of FLT was optimized at B3LYP/6-311G (d,p) theoretical level. The obtained results clearly demonstrate the energy stability of the optimized geometries and obviously show that the nature of Flutamide adsorption energy on the surface of SWCNT is in the range of the physisorption. Afterwards, the various structures of SWCNT (5, 5) and the adsorption of FLT on the outer surface of SWCNT (5, 5) was investigated using DFT method. The energies of FLT, SWCNT (5, 5), Zn doped SWCNT (5, 5), HOMO and LUMO orbitals, gap energy and dipole moments were calculated using DFT and MO methods.