A UV radiation-based surface disinfection system disinfects contaminated surfaces by providing disinfecting UV radiation that eliminates pathogens or microbes from the target surface that it irradiates/illuminates. The system includes a housing adapted to contain UV radiation sources and operate as a UV shield and director, at least one UV radiation (light) emitting source mounted within said housing for providing disinfecting UV radiation from said housing onto a target surface, and at least one of a range sensor and timer. UV radiation source(s) can be mounted on a rotating or sliding assembly within the main assembly to disinfect the preferred surface. The UV radiation source(s) can also be mounted in a portable handheld assembly having a range sensor for enhanced safety during use. The system can be powered by standard AC electrical power or batter sources.