The properties of the BF 4− n (R)n- anions (where R=CH 3 , C 2 H 5 and n=1–4) were investigated at the ab initio OVGF/6-311++G(3df,3pd)//MP2/6-311++G(d,p) level of theory. It is shown that subsequent replacement of the fluorine ligands with alkyl groups in the BF4- superhalogen anion results in a substantial electronic stability decrease (by 1.13–3.42eV), however, even the fully substituted B(CH3)4- and B(C2H5)4- anions remain stable and relatively strongly bound (by ca. 4.3–4.4eV) negatively charged systems. The presence of four substituents bound to the boron atom is identified as the most important factor that enables the existence and stability of the BF 4− n (R)n- anions.