This work investigates the antibacterial potential of TiO2‐based glass‐ceramic. A glass of TiO2 microcrystals embedded in glass matrix of BaO‐TiO2‐B2O3was obtained by melt quench method followed by controlled heat treatment at the 650°C for 3 hours. Crystallization of anatase phase of TiO2 was confirmed by X‐ray diffraction. UV‐visible absorbance and photoluminescence were also recorded. Interestingly band gap of TiO2 glass‐ceramic (crystallized glass) was found to be 2.9 eV. Crystallized glass showed excellent antibacterial property against Escherichia coli in both forms (powder and plate). More than 90% of disinfection was achieved by photocatalytic TiO2 glass‐ceramic surface within one hour of sunlight exposure, which was significantly higher than as‐quenched glass surface and TiO2 glass‐ceramic surface under dark. Intracellular reactive oxygen species (ROS) intensity of bacterial cells in the presence of crystallized glass was almost three times higher than the control and as‐quenched glass under light. Higher production of ROS is major factor for bacterial degradation on crystallized glass surface.