The optical properties of the solutions of the MDMO-PPV light-emitting polymer were investigated. The maximum mass extinction coefficient values of the solutions of the MDMO-PPV for 6.640 and 3.014 A mu M were found to be 20.874 and 42.009 L g(-1) cm(-1), respectively. The absorption band edge values of the solutions of the MDMO-PPV shifted from 2.149 to 1.987 eV with increasing molarity. To obtain lower E-g values (2.020, 2.057, 2.083, 2.088 and 2.103 eV, respectively) of the MDMO-PPV can be preferred xylene, toluene, chlorobenzene, chloroform and tetrahydrofuran solvents, respectively. The E (g) of the solution of the MDMO-PPV was decreased with molarities and solvents. The refractive index values of the MDMO-PPV were controlled with various solvents. The optical parameters such as single oscillator energy, dispersion energy, M (-1), M (-3) moments, optical oscillator strengths, linear static refractive index, optical linear susceptibility, third-order nonlinear susceptibility and nonlinear refractive index were calculated using Wemple-DiDomenico equation. The highest contrast was obtained with xylene, while the lowest contrast was obtained with chlorobenzene. The MDMO-PPV can be used in the fabrication of the metal-semiconductor contacts due to low optical band gap and suitable optical parameters. Also, the surface morphology properties of the MDMO-PPV polymer film were investigated.