This Practice Note discusses the importance of in-house law departments' use of key performance indicators (KPIs) to track, measure, document, and improve their performance. Topics covered include the definition of KPIs, how they differ from metrics, and the many benefits KPIs can provide to organizations, law departments, and department personnel. Additional information includes sample KPIs for law departments to customize and adopt and best practices to assist law departments effectively develop, introduce, track, use, and improve KPIs.