•Three new ternary complexes of sulfaquinoxaline were synthesized and characterized.•Intra and intermolecular contacts stabilize the crystal structure of the complexes.•Zn complex is more cytotoxic against tumoral cells than the Ni and Cu compounds. Three monomeric ternary complexes of Ni(II) (1), Cu(II) (2), and Zn(II) (3) with sulfaquinoxaline (SQO), and 2,2’-bipyrimidine (bpm) as ligands have been prepared and their crystal structures have been determined. The complexes are formulated as M(SQO)2bpm·2H2O, completing MN6 coordination spheres. Hirshfeld surface analysis was employed to study the intermolecular interactions in the crystal lattices of the compounds. From these studies, it was found that hydrogen bonding and π-stacking interactions play an important role. Besides, the complexes have been characterized by FTIR and UV-Visible spectroscopies, and thermogravimetric techniques. The cytotoxicity of the complexes was screened against the tumoral A549 (human lung adenocarcinoma) and MG-63 (human osteosarcoma) cell lines. The complexes showed enhanced antibacterial activity against S. aureus and S. epidermidis as compared with the free SQO ligand.