Accurate determination of fluid status in patients with heart failure is a critical aspect of care of this population. Early detection of emerging fluid overload would allow for prompt intervention, potentially aborting clinical deterioration and avoiding hospitalization. While many strategies are available to determine fluid status of patients, all areas are compromised by less-than-optimal sensitivity and specificity. Recent work on the role of bioimpedance as a means of assessing a patient's fluid status indicates that this parameter may have a role in monitoring patients with heart failure. This article reviews present techniques available for assessment of fluid status and focuses on the additional information provided by bioimpedance assessment. Congest Heart Fail. 2010;16(4)(suppl 1):S52–S55. ©2010 Wiley Periodicals, Inc.