Hand hygiene by health care personnel is an important measure for preventing health care–associated infections, but adherence rates and technique remain suboptimal. Alcohol-based hand rubs are the preferred method of hand hygiene in most clinical scenarios, are more effective and better tolerated than handwashing, and their use has facilitated improved adherence rates. Obtaining accurate estimates of hand hygiene adherence rates using direct observations of personnel is challenging. Combining automated hand hygiene monitoring systems with direct observations is a promising strategy, and is likely to yield the best estimates of adherence. Greater attention to hand hygiene technique is needed.