Crystals of the title salt, (C 8 H 20 N)[Sn(C 6 H 5 ) 3 (C 2 H 2 O 2 S)], comprise diisobutyl-ammonium cations and mercapto-acetato-tri-phenyl-stannate(IV) anions. The bidentate binding mode of the mercapto-acetate ligand gives rise to a five-coordinated, ionic tri-phenyl-tin complex with a distorted cis -trigonal-bipyramidal geometry around the tin atom. In the crystal, charge-assisted ammonium-N-H⋯O(carboxyl-ate) hydrogen-bonding connects two cations and two anions into a four-ion aggregate. Two positions were resolved for one of the phenyl rings with the major component having a site occupancy factor of 0.60 (3).