Healthcare information systems (HIS) play a vital role in quality of care and the organization's daily operations. Consequently, increasing numbers of clinicians have been involved in HIS implementation, particularly for clinical information systems (CIS). Implementation of these systems is a major organizational investment, and its outcomes must be assessed. The purpose of this article is to provide clinicians and frontline informaticians with a practical guide to assess these outcomes, focusing on outcome variables, assessment methods, and timing of assessment. Based on in-depth literature reviews and their empirical experiences, the authors identified 3 frequently used outcomes: user satisfaction, clinical outcomes, and financial impact. These outcomes have been assessed employing various methods, including randomized controlled trials, pre- and post-test studies, time and motion studies, surveys, and user testing. The timing for outcomes assessments varied depending on several factors, such as learning curves or patients conditions. In conclusion, outcomes assessment is essential for the success of healthcare information technology, and the CIS implementation team members must be prepared to conduct and/or facilitate these studies.