Physical, chemical and biological constituents such as organic compounds and microorganisms are released by wastewaters from fabrics, homes, facilities and other resources. Bacteria, viruses and fungi can be described as microbial pollutants. In this study the disinfection of Escherichia coli O157:H7 strain from the wastewater was aimed by using ultrasound power and ultraviolet light intensity. The 60% amplitude of ultrasound energy and also, 88 W/m2 light intensity at 254 nm wavelength was used. The ultrasound source was an ultrasonic generator and the ultraviolet light source was Pen-Ray ultraviolet lamp. The temperature was constant at 37°C temperature and the amount of TiO2 was 300 mg during the experiments. For investigating the effect of ultrasound energy, it was used alone to the system. Also, for the effect of ultraviolet light, it was used alone to the system. For the synergistic effect of ultrasound and ultraviolet, they were used together to the system. The results showed that the completely disappearance was seen at 30 min. when the ultraviolet light (UV) was used alone, 40 min. when the ultrasound (US) was used alone and 8 min when the ultrasound and the ultraviolet light were used simultaneously. The most disinfection was determined when the ultrasound and the ultraviolet light were used simultaneously. Together using of the sound and light energies proved to be the most effective process on bacterial disinfection by generating greater •OH radicals. Also, having more piercing and devastating properties of 254 nm wavelength, it was seen more effective disinfection in this study.