ABSTRACTBACKGROUND We assessed the effectiveness of a handwashing program using hand sanitizer to prevent school absenteeism due to upper respiratory infections ( URIs ).METHODS This was a randomized, controlled, and open study on a sample of 1341 children 4‐12 years old, attending 5 state schools in Almería (Spain), with an 8‐month follow‐up. The experimental group ( EG ) washed their hands with soap and water, together with using hand sanitizer, and the control group followed their usual handwashing procedures. Absenteeism rates due to URIs were compared between the 2 groups through a multivariate Poisson regression analysis. The percent of days missed in both groups were compared with a z test.RESULTS Overall, 1271 cases of school absenteeism due to URIs were registered. Schoolchildren from the EG had a 38% lower risk of absenteeism due to URIs , incidence rate ratio: 0.62, 95% confidence interval: 0.55‐0.70, and a decrease in absenteeism of 0.45 episodes/child/academic year, p < .001. Pupils missed 2734 school days due to URIs and the percentage of days absent was significantly lower in the EG , p < .001.CONCLUSIONS Use of hand sanitizer plus handwashing with soap accompanied by educational support is an effective measure to reduce absenteeism due to URIs