In the title compound, [SbBr(C10H7)2], the Sb(III) atom has a distorted trigonal-pyramidal coordination geometry and the planes of the two naphthalene ring systems make a dihedral angle of 80.26 (18)°. An intra-molecular C-H⋯Br hydrogen bond forms an S(5) ring motif. In the crystal, weak C-H⋯Br inter-actions link the mol-ecules into helical chains along the b-axis direction.