A series of Zn1-xCoxSe (x=0, 0.025, 0.050, 0.075, and 0.100) films using were evaporated (thickness of 1m) using electron beam gun. The effect of Co doping on the structural, optical, and magnetic properties has been investigated. X-ray diffraction studies confirm formation of zinc blend structure for all Zn1-xCoxSe films. The crystallite size increases and the lattice strain decreases with the increase in Co content. The elemental constituents were characterized by energy dispersive X-ray. Optical studies showed an increase in refractive index and a decrease in energy gap with the increase in the cobalt doping. The dispersion of the refractive index has been analyzed in terms of the Wemple-DiDomenico single oscillator model. The oscillator parameters including the single oscillator energy (E-o), the dispersion energy (E-d), and the static refractive index (n(0)) were estimated. Magnetization measurements via vibrating sample magnetometer showed a hysteresis loop and confirmed room-temperature ferromagnetism in Co-doped ZnSe films.