['To use quality-improvement (QI) methods to develop and test a multimodal intervention to improve hand-hygiene compliance among health care workers (HCWs) to >90%.', "We used a quasi-experimental staggered intervention that was conducted on 2 similar general pediatric units within a 475-bed tertiary children's hospital. Compliance was defined as acceptable hand hygiene both before and after contact with the patient or the patient's care environment. Measurement of HCW hand-hygiene compliance was performed by covert observations made during routine patient care. Twelve months of preintervention data were collected. QI methods were used to test and implement interventions sequentially in each unit. Interventions addressed leadership support, improving HCW knowledge, hand-hygiene supply availability, and HCW behavior.", 'Interventions began on unit A on November 10, 2008. Similar interventions were later tested on unit B starting March 23, 2009. By April 1, 2009, compliance increased on unit A (from 65% to 91%) and unit B (from 74% to 92%). Improvement on each unit occurred only after the interventions were introduced. Identifying HCWs who failed to perform hand hygiene and offering alcohol-based hand rub to them before patient contact resulted in the greatest improvement. Improvements were sustained on both units for 18 months.'] Does quality-improvement initiative sustain improvement in pediatric health care worker hand hygiene?