This prospective, three-phase, observational intervention study on hand hygiene compliance (HHC) during haemodialysis treatment was conducted at the University Hospital of the RWTH Aachen University between March and September 2010. Optimized hand hygiene standard operating procedures (SOPs) for dialysis connections (intervention I) and disconnections (intervention II) were implemented during two intervention periods. Observations were carried out during three observation phases (phase I, II, III), which were divided by two 2-week intervention phases (intervention I, II). HHC was assessed according to the '5 Moments for hand hygiene' (WHO). A total of 8,897 indications for hand disinfections were observed. The mean number of performed hand disinfections per dialysis procedure increased from 6 before interventions (phase I) to 9 after interventions I and II (phase III). Indications for hand disinfections per dialysis procedure decreased from 21 (phase I) to 15 (phase III). The overall hand hygiene compliance improved from 30% in phase I to 62% in phase III. Considering all three observation phases, the highest compliance rate was achieved for the indication ‘before touching a patient’ in phase III (88 %). The greatest improvement of 148%, however, was observed for the indication ‘before clean/aseptic procedures’ (from 21 % in phase I to 52% in phase III), which is the indication with the greatest impact on preventing healthcare-associated infections.