There is an urgent need to capture and record data related to clinical outcomes, but there are many barriers. The range of problems includes lack of agreement on conceptualization of the term "outcome," inadequate measures of outcomes, and inadequate information systems to capture and manipulate data that would reflect outcomes. This article focuses on information system requirements to capture, store, and utilize clinical outcome data. For greatest accuracy, outcome data should be captured as close to the source as possible, including direct data capture from patients themselves and from their families. To make maximum use of outcome data, systems must be designed to 1) store data in multipurpose databases; 2) share data across different platforms; 3) link outcome data to other data that might influence or explain outcomes; 4) allow querying of the data by authorized personnel; and 5) protect patient confidentiality.