 A cluster randomised, controlled and open study of 2 cohorts of primary school children between the ages of 4 and 12, attending 5 Public Schools in a geographic area of the Almería province Spain. This study was carried out throughout the 8 months of an academic year October 2009 to May 2010. The experimental group washed their hands with soap and water, complemented with hand sanitizer, while the control group followed usual hand washing. The parents of both groups completed the survey on sociodemographic characteristics and questions about hand hygiene referred to when and how their children wash their hands Progenitors of children who were absent from school collected upper respiratory infections symptoms and handed in the completed form to the teacher. One Research assistant collected the absence sheets of the participating classes weekly, telephoned the parents of absent children to enquire about the cause of their absence, visited the classrooms and collaborated with the teachers in hand hygiene related activities. 