AIM: To assess the clinical value of malignancy grading systems compared with nuclear DNA content, protein p53, and angiogenesis for predicting recurrence of stage I (UICC, 1987) tongue carcinomas. METHODS: Histopathological malignancy grading according to Jakobsson and tumour front grading according to Bryne et al were performed on haematoxylin and eosin slides. DNA analysis was performed by image cytometry. Protein p53 and angiogenesis were evaluated by immunohistochemical analysis using antibody CM1 and antibody against factor VIII related antigen, respectively. RESULTS: 49 patients with stage I carcinomas of the mobile tongue were included, all treated by local surgical excision alone. Eight patients (16%) suffered from local recurrence during follow up, and 13 (27%) had regional recurrence. Both Jakobsson's malignancy grading system and p53 immunoreactivity proved to be useful predictors of regional recurrence in a Cox multivariate regression analysis. CONCLUSIONS: Histopathological malignancy grading systems provide valuable prognostic information and can still compete with current biological markers in this respect.