In the title compound, [Ru(C9H10BN6)Cl(C3H4N2)(C18H15P)], the RuII atom is coordinated by an N,N′,N′′-tridentate hydridotrispyrazolylborate (Tp) ligand, a pyrazole (HPz) molecule, a chloride ion and a triphenylphosphine ligand, resulting in a distorted RuClPN4 octahedral coordination for the metal ion: the tridentate N atoms occupy one octahedral face and the Cl and P atoms are cis. One of the phenyl rings is disordered over two orientations in a 0.547 (10):0.453 (10) ratio, and a weak intramolecular N—H⋯Cl hydrogen bond generates an S(5) ring