Academic liaison--the two-way communication between a particular academic area and the library, focused through an individual or group of library staff--has received little attention in the debate about performance measurement. Changes have taken place in higher education libraries in both scale, with the growth of student numbers, and intent, with the move from being passive book depositories to becoming partners in course delivery. Academic liaison activities include: committee or course board membership; user education; materials selection and collection development; bookfund management; advice and assistance; developing and maintaining subject awareness; cataloging and classification; course planning and development; and monitoring the feedback loop. Liaison relationships are with: individual academics and student researchers; academic management; library representatives and committees; course teams and subject groups; students; administrative staff; and other library staff. The paper discusses the context of the higher education library; importance of the academic liaison; definition of the academic liaison position; how to measure the effectiveness of a liaison; and if measuring liaison performance will have any significance. A consensus view on the definition of an academic liaison is a prerequisite to measuring effectiveness. (SWC)