Lithium salts have been used in medicine for over a century and are a widely accepted treatment. Clinical practice in the London borough of Barnet led us to suspect that agreed guidelines were not being followed. We checked them against published guidelines and followed up their implementation. A list of patients on lithium was obtained from the local biochemistry laboratory and a representative sample extracted. We looked at the frequency of laboratory testing and compared it with the guidelines. We found that the standards for lithium therapy follow-up were not being met and that while we awaited the outcome of our consultant psychiatrists' committee deliberations, the recommendations were not being implemented. A lithium register or clinic needs to be established in the area, and there is also a need for more reliable and effective implementation of clinical audit recommendations.