To evaluate the effectiveness of an intensive hand hygiene campaign on reducing absenteeism caused by to influenza-like illness (ILI), diarrhea, conjunctivitis, and laboratory- confirmed influenza, we conducted a randomized control trial in 60 elementary schools in Cairo, Egypt. Children in the intervention schools were required to wash hands twice daily, and health messages were provided through entertainment activities; Data were collected on student absenteeism and reasons for illness. School nurses collected nasal swabs from students with ILI, which were tested by using a qualitative diagnostic test for influenza A and B. Compared with results for the control group, in the intervention group, overall absences caused by ILI decreased (reduced 40%, p<0.0001), diarrhea (reduced 30%, p<0.0001), conjunctivitis (reduced 67%, p<0.0001), and laboratory-confirmed influenza (reduced 50%, p<0.0001). An intensive hand hygiene campaign was effective in reducing absenteeism caused by these illnesses.