OBJECTIVE. To elucidate behavioral determinants of handwashing among nurses. DESIGN. Statistical modeling using the Theory of Planned Behavior and relevant components to handwashing behavior by nurses that were derived from focus-group discussions and literature review. SETTING. The community and 3 tertiary care hospitals. PARTICIPANTS. Children aged 9-10 years, mothers, and nurses. RESULTS. Responses from 754 nurses were analyzed using backward linear regression for handwashing intention. We reasoned that handwashing results in 2 distinct behavioral practices-inherent handwashing and elective handwashing-with our model explaining 64% and 76%, respectively, of the variance in behavioral intention. Translation of community handwashing behavior to healthcare settings is the predominant driver of all handwashing, both inherent (weighted β = 2.92) and elective (weighted β = 4.1). Intended elective in-hospital handwashing behavior is further significantly predicted by nurses' beliefs in the benefits of the activity (weighted β = 3.12), peer pressure of senior physicians (weighted β = 3.0) and administrators (weighted β = 2.2), and role modeling (weighted β = 3.0) but only to a minimal extent by reduction in effort (weighted β = 1.13). Inherent community behavior (weighted β = 2.92), attitudes (weighted β = 0.84), and peer behavior (weighted β = 1.08) were strongly predictive of inherent handwashing intent. CONCLUSIONS. A small increase in handwashing adherence may be seen after implementing the use of alcoholic hand rubs, to decrease the effort required to wash hands. However, the facilitation of compliance is not simply related to effort but is highly dependent on altering behavioral perceptions. Thus, introduction of hand rub alone without an associated behavioral modification program is unlikely to induce a sustained increase in hand hygiene compliance.