This research utilizes density functional theory (DFT) to explore the electronic and optical characteristics of BaLiX3 (X = Br, Cl, I) using the WIEN2K simulation package which uses full potential linear augmented plane wave method (FP-LAPW). Investigation of electronic properties is done by calculating band structure of BaLiX3 using Local Spin Density Approximation (LSDA) and Generalized Gradient Approximation (GGA-PBE). Density of States (DOS) of BaLiX3 have been thoroughly investigated in this research work. This study found that BaLiCl3, BaLiBr3 and BaLiI3 have indirect energy band gaps at R → Γ symmetry points. To understand optical properties, our calculation provides detailed insight into the material’s dielectric function, absorption coefficient, and refractive index. This study is also establishing the comparison between pseudo-potential and full potential approaches in the Density Functional Theory (DFT).