Indoor air pollution is caused by particulate matter and chemical and microbial contamination. Conventional technologies, including filteration, do not adequately, provide complete answers to these problems. Photocatalytic oxidation combined with filteration provides one of the most viable solutions to the problem of indoor air contamination by microorganisms and volatile organic chemicals (VOCs). It can also provide a defense against bioterrorism. This paper describes the theoretical background of the technology and results of its effectiveness against VOCs, bacteria, spores, and dust mite allergens. Although the technology uses UV photons from blacklight, it can be designed to use sunlight with the help of fiber optics.