A three-dimensional potential energy surface (PES) for the Br --H 2 complex is computed using the ab initio CCSD(T) method and an extended basis set. The PES has two equivalent minima at the linear geometries (equilibrium interfragment distance R e=3.34 Å and interaction energy D e=610 cm -1) separated by the barrier at the T-shaped configuration (interfragment distance R e=4.03 A and barrier height of 610 cm -1). Ab initio points are fitted to a flexible analytical form and used in the variational rovibrational energy level calculations. Simulated infrared spectra of the Br --H 2 and Br --D 2 complexes in the monomer stretching excitation region are in good agreement with the measured ones. Nonstatistical intensity ratios of the complexes of para- and ortho-monomers are qualitatively explained by monomer ligand exchange reactions. Predissociation of the complexes containing vibrationally excited monomers is analyzed and shown to proceed through the near-resonant vibration-to-rotation energy transfer. For complexes involving Br - and the HD monomer, two energetically low-lying states are predicted, corresponding predominately to the Br --DH and Br --HD isomeric forms. The results demonstrate the close similarity of the bromide containing complexes to their analogs containing the chloride anion.