A reaction of [Cp*RuCl](4) (Cp* = eta(5)-C-5(CH3)(5)) with K[HB(aza)(3)] (aza = 7-azaindolyl) afforded the first organometallic HB(aza)(3)(-) complex [Cp*Ru{HB(aza)(3)-kappa H-3,N,N'}], which lost one of the aza-units coordination upon treatment with carbon monoxide to give the mono(carbonyl) complex [Cp*Ru{HB(aza)(3)-kappa H-2,N}(CO)]. The crystal structures of these complexes have been determined by X-ray crystallography.