Synthesis of the phase formerly reported as Ba5Ga6 succeeds only in the presence of hydrogen. The heavy atom structure of Ba5Ga6H2 has been redetermined by single-crystal X-ray diffraction (trigonal P3cl, Z = 2, a = 7.7698(2) Angstrom, c = 14.3902(7) Angstrom), and the hydrogen positions have been elucidated by time-of-flight neutron powder diffraction, The unit cell contains isolated slightly distorted octahedra Ga-6(8-) with barium cations over all edges. Hydride is bound in two types of barium tetrahedra [d(Ba-H) = 2.61-2.62 Angstrom]. The stoichiometry is appropriate for a Zintl phase : (Ba2+)(5)Ga-6(8-)(H-)2.