A novel thiourea derivative, N-((2-chloropyridin-3-yl)carbamothioyl) thiophene-2-carboxamide,C11H8ClN3OS2(HL) and its Co(II), Ni(II) and Cu(II) complexes (ML2 type) were prepared and characterized by elemental analysis, FT-IR,H-1 NMR and HR-MS methods. The crystal structure of HL was also investigated by single crystal X-ray diffraction study. The HL crystallizes in the orthorhombic crystal system with P 2(1)2(1)2(1) space group, Z= 4, a = 3.8875(3) angstrom, b = 14.6442(13) angstrom, c = 21.8950(19) angstrom. The [ML2] complex structures were optimized by using B97D/TZVP level. Molecular orbitals of HL ligand were calculated at the same level. Thermal and electrochemical behaviors of the complexes were investigated. Anticancer and antioxidant activities of the complexes were also investigated. Antioxidant activities were determined by using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) assays. Anticancer activities were studied via MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay in MCF-7 (Michigan Cancer Foundation-7) breast cancer cells. (C) 2017 Elsevier B.V. All rights reserved.