The prime objective of tumour ablation in oral squamous cell carcinoma (OSCC) is the removal, with a ‘margin’ of normal tissue, of the whole tumour. Definition of what constitutes margin involvement varies. This study aims to examine the factors associated with close and involved surgical margins in the management of OSCC. A cohort of 200 consecutive patients with previously untreated OSCC provided the material for the study. Various clinical, operative and pathological parameters were related to the status of the surgical margin, as well as time to recurrence, and survival. Cox regression analysis of the survival was also undertaken. Of the 200 patients 107 (53.5%) had clear margins, 84 (42%) close and 9 (4.5%) involved. Poor correlation was found between the status of the surgical margin and clinical factors, but in contrast high correlation between histological indicators of aggressive disease and close or involved surgical margins. These results imply that close surgical margins in OSCC could be regarded as an indictor of aggressive disease.