AIMS: To audit the content of primary cutaneous malignant melanoma histopathology reports with special reference to Breslow thickness and lateral excision margins. METHODS: The Trent Regional Cancer Registry was asked to provide details of primary cutaneous malignant melanomas for the most recent year available (1990). Histopathology departments were then requested to provide copies of the relevant reports, which were then analysed. RESULTS: In total, 178 reports were obtained from 16 departments. Breslow thickness was present in 87.1% (155/178) and a comment had been made on lateral excision in 85.4% (152/178). A specific clearance measurement was recorded in 5.6% (10/178), and in 9.6% (17/178) tumour was stated to extend to the margin. In 4.5% (8/178) neither thickness nor a comment on excision was recorded. Clinical advice on excision was offered in 12.4% (22/178). A macroscopic description was absent in 6.7% (12/178). CONCLUSIONS: Deficiencies were identified in the quality of malignant melanoma histopathology reports in Trent Region. There is no reason to believe that significant improvements have occurred since 1990 or that other regions are performing differently. A national standard for reporting primary cutaneous malignant melanoma is recommended. As a minimum, all reports should include Breslow thickness and a specific measurement of lateral clearance. This will facilitate prognostic evaluation, clinical management and audit. This standard would not exclude the reporting of other information, depending on local policy. As with all standards, continual review must be undertaken and consideration given as to whether other more recent parameters, such as growth phase, also warrant future inclusion.