The results of spectrophotometric study and quantum chemical calculations for copper(II) chloro- and bromocomplexes in acetonitrile are reported. Electronic spectra of the individual copper(II) halide complexes were obtained in a wide spectral range 200–2200 nm. Stability constants of the individual copper(II) halide complexes in acetonitrile were calculated: log β₁ = 8.5, log β₂ = 15.6, log β₃ = 22.5, log β₄ = 25.7 for [CuCl_n]²⁻ⁿ and log β₁ = 17.0, log β₂ = 24.6, log β₃ = 28.1, log β₄ = 30.4 for [CuBr_n]²⁻ⁿ. Structures of the studied complexes were optimized and electronic spectra were simulated using DFT and TD-DFT methodologies, respectively. According to the calculations, the more is the number of halide ligands the less is coordination number of copper ion.