The Acromegaly Consensus Group met in April 2009 to revisit the guidelines on criteria for cure as defined in 2000. Participants included 74 neurosurgeons and endocrinologists with extensive experience of treating acromegaly. EVIDENCE/CONSENSUS PROCESS: Relevant assays, biochemical measures, clinical outcomes, and definition of disease control were discussed, based on the available published evidence, and the strength of consensus statements was rated. Criteria to define active acromegaly and disease control were agreed, and several significant changes were made to the 2000 guidelines. Appropriate methods of measuring and achieving disease control were summarized.