Zn1-xSmxO (x = 0.01, 0.02, 0.03, 0.04) nano particles were prepared using low temperature solution combustion method. The X-ray diffraction shows that all the prepared samples are formed in single phase with hexagonal wurtzite structure. SEM images show the agglomeration of nano particles for higher concentration of samarium. Photoluminescence studies undoped ZnO shows appearance of more intense sharp blue emission at 451nm and less intense distinct peaks are appeared at 482, 492, 521 nm and Samarium doped ZnO nano particles exhibit the two emission bands in the red wavelength region, 4G5/2 to 6H9/2 (651 nm) and 4G5/2 to 6H7/2 (704 nm). The emission 4G5/2 to6H9/2 (651 nm) is an electric dipole transition of ∆J =  ± 2 and 4G5/2 to 6H11/2 (704 nm) refers to forbidden transition of ∆J =  ± 3 having very less intensity. TL measurements are performed under the gamma irradiation dosage of 0.05 – 10 kGy. The TL intensity is maximum for the 2% Sm doped ZnO particles. Samarium doped ZnO nano particles shows TL glow peak at 439 ̊ C and the TL intensity increases with gamma dose. The kinetic parameters are calculated by using glow curve shape method.