Methotrexate is commonly used for the treatment of psoriasis. It has potentially serious side-effects and effective monitoring is essential. We conducted an audit to compare our current use of methotrexate with established guidelines and to highlight areas for improvement. The case notes of 40 patients on maintenance treatment with methotrexate were reviewed. There were inadequacies in documentation of alcohol history, baseline investigations and test dose of methotrexate. The riming of liver biopsies was not always based on cumulative dose of methotrexate. Information given to patients and general practitioners was felt to be inadequate. As a result of the audit, standard forms have been introduced to document details at the start of treatment, monitoring investigations and cumulative methotrexate dose. Information for patients and general practitioners have been designed and are used regularly. Increased awareness should result in increased patient compliance and earlier hospital referral should side-effects arise. This type of audit is directly relevant to other potentially dangerous drugs and could result in improved clinical practice in other areas.