The sedge family, Cyperaceae, is the third largest family of monocotyledonous plants. They are of significant economic importance, especially among rural communities in the tropics, where sedges are intensively used. The World Checklist of Cyperaceae is a unique resource that lists all validly published names of sedges, providing the source of their publication and indication of which names are currently accepted and which are synonyms. It will be a standard nomenclatural reference for further research into this important family.