A set of complexes L2HB center dot center dot center dot BeX2 (L = CNH, CO, CS, N-2, NH3, NCCH3, PH3, PF3, PMe3, OH2; X = H, F) containing a boron-beryllium bond is described at the M06-2X/6-311+G(3df,2pd)//M062-2X/6-31+G(d) level of theory. In this quite unusual bond, boron acts as a Lewis base and beryllium as a Lewis acid, reaching binding energies up to -283.3 kJ/mol ((H2O)(2)HB center dot center dot center dot BeF2). The stabilization of these complexes is possible thanks to the sigma-donor role of the L ligands in the L2HB center dot center dot center dot BeX2 structures and the powerful acceptor nature of beryllium. According to the topology of the density, these B-Be interactions present positive laplacian values and negative energy densities, covering different degrees of electron sharing. ELF calculations allowed measuring the population in the interboundary B-Be region, which varies between 0.20 and 2.05 electrons upon switching from the weakest ((CS)(2)HR center dot center dot center dot BeH2) to the strongest complex ((H2O)(2)HB center dot center dot center dot BeF2). These B Be interactions can be considered as beryllium bonds in most cases.