Hand hygiene is a key element in preventing the transmission of cold and flu viruses. The authors conducted an experimental-control design study in 4 campus residence halls to determine whether a message campaign about hand hygiene and the availability of gel hand sanitizer could decrease cold and flu illness and school and work absenteeism. Their findings indicate that students who were exposed to the message campaign and provided with gel hand sanitizer increased their knowledge about the potential health benefits of hand washing and sanitizer use; they reported higher rates of hand washing and using sanitizer than did the control group. These students also experienced fewer cold and flu illnesses during the study than those in the control group and missed fewer class or work engagements because of colds or flu. Conducting a health promotion campaign in residence halls may therefore help prevent colds and flu and decrease absenteeism on university campuses.Key Words: absenteeism, colds, college students, hand washing, upper respiratory infection