The authors reviewed the influencing factors of staff compliance with hand washing in various studies, so as to update policies on this practice necessary for the prevention of nosocomial infections. 38 studies were selected; despite the fact that it was not always easy to compare the results, some converging factors appeared. The level of compliance was most of the time inferior to 50 %, especially among physicians. The number of sinks available was important for compliance but motivation and assessment played a more important role. The impact of training was positive if the training itself was carried out on an active basis by analysising of mistakes and care given, and if it was supported by regular assessment together with a return of the data to the assessed departments. Knowing about the patient's infection status: generally improved compliance with hygiene, going against universal caution, still badly observed in most hospitals. Some points needed to be more thoroughly studied so as to evaluate the improvement of compliance with hydro-alcoholic solutions, to integrate hand washing in work; load studies, and to better define hand washing instructions according to the nature of contact and to the wearing of gloves. The studies illustrated the complexity and multifactorial character of hand washing. The staffs (especially physicians) motivation, must be stimulated by integrating it within the dynamics of care quality and ergonomy. The methods to be used still remain to be determined but it seems that traditional methods such as posters or theoretical lectures must be abandoned for more modern techniques of communication and assessment. The staff's representation of contagious diseases needs to be better assessed in order to obtain suitable and rational behaviors.