The primary purpose of this quasi-experimental research is to observe health care workers compliance with hand-hygiene guidelines during patient care in an intensive care unit in Ireland before (pretest) and after (posttest) implementation of a multifaceted hand-hygiene program. Health care workers attitudes, beliefs, and knowledge in relation to compliance with handwashing guidelines were also investigated. A convenience sample of nurses, doctors, physiotherapists, and care assistants (n = 73 observational participants, n = 62 questionnaire respondents) was used. Data (N = 314 observations, 62 questionnaires) were analyzed descriptively and cross-tabulated using chi-square (Pearsons) and Mann-Whitney statistical tests. Results revealed that a significant shift (32%) occurred in health care workers compliance with handwashing guidelines (pretest 51%, posttest 83%, p < .001) following the interventional hand-hygiene program. Significant changes were also found in relation to health care workers attitudes, beliefs, and knowledge (p < .05).