The molecular structure and vibrational spectra of α-chloro and α-bromo derivatives of tris(acetylacetonato)chromium(III), Cr(ClAA)3 and Cr(BrAA)3, were investigated using the density functional theory (DFT) calculations. The geometrical parameters and harmonic vibrational wavenumbers of the titled compounds were obtained at the B3LYP level, using 6-311 + G(d) and 6-31G** basis sets. The calculated vibrational wavenumbers were compared with the corresponding experimental results and those of tris(acetylacetonato)chromium(III), Cr(AA)3. The effects of chlorine and bromine substitutions at the α-position on the vibrational spectra and geometry of Cr(AA)3 were studied. The α-halo substitution effects were also investigated using the natural bond orbital, NBO, analysis.