Ultraviolet germicidal irradiation (UVGI) is one method currently used to reduce transmission of airborne infectious diseases such as tuberculosis. UVGI is defined as optical radiation in the shortwave UV-C spectrum capable of killing microorganisms and has been demonstrated to be effective against certain airborne bacteria. Because prolonged direct exposure to low intensity UVGI can cause skin and eye irritation, fixtures appropriate for upper room air disinfection are installed above eye level and designed to limit the vertical emission spread to prevent excessive exposure to occupants. Accurate UVGI fixture emission profiles, in combination with appropriate room ventilation measurements, are needed to calculate the dose to airborne microorganisms and estimate the effectiveness of these air disinfection devices in preventing disease transmission in susceptible populations. Manufacturers of fixtures usually provide nominal wattage and horizontal centerplane intensity levels, but to quantify the dose to exposed airborne microorganisms adequately in realistic room applications it is necessary to measure the three-dimensional emission profile for various fixture designs. This article evaluates several UVGI fixtures available for upper room installations and illustrates practical methods for evaluating effective radiation output. Typical emission diagrams are included.