The aim of this study was to fabricate needle like-TiO 2 /polyrhodanine nanostructures by polymerizing rhodanine monomer on the TiO 2 nanoparticles' surfaces and investigate their antibacterial activities. The structural, thermal, morphological, surface and electrical properties of non-covalently functionalized nanoparticles were characterized by using FTIR, XPS, elemental analysis, TGA, XRD, SEM-EDX, TEM, contact angle, and conductivity measurements. Characterization results confirmed the formation of needle like-TiO 2 /polyrhodanine (PRh) core/shell hybrid nanostructures. Alterations on the surface and electrokinetic properties of the materials were characterized by zeta (f)-potential measurements with the presence of various salts and surfactants. The f-potential of needle like-TiO 2 was observed to increase from 27.6 mV to 128.4 mV after forming a core/shell needle like-TiO 2 /PRh nanocomposite structure and with the presence of cetyltrimethyl ammonium bromide (CTAB) surfactant. Thereby colloidally more stable dispersions were formed. Antibacterial properties of needle like-TiO 2 /PRh were also tested against Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli by various methods and they showed good antibacterial activity. The highest killing efficiency was determined for needle like-TiO 2 /PRh against E. coli by colony-counting method as 0.95. TEM experiments also showed the immobilizations of the nanoparticles on E. coli and revealed the interactions between E. coli and the nanoparticles.