OBJECTIVE To determine the interrelationship of histological grade and nuclear morphometry and to compare their prognostic significance in patients with localized renal cell carcinoma (RCC). METHODS A retrospective prognostic study of 39 patients with localized (pT1, pT2) RCC was performed. Conventional histological grade and nuclear morphometry were assessed independently and the correlation between these grading systems and their impact on the patients' outcome were evaluated. RESULTS Histological grade and the nuclear morphometric variables were significantly correlated: the strongest association was that between grade and the nuclear regularity factor. The best predictor of disease-free interval and survival (by univariate analysis) was the combination of nuclear area and nuclear elongation factor, followed by conventional tumour grade, nuclear elongation factor, nuclear regularity factor and nuclear area. However, a multivariate analysis showed that the only independent prognosticator for survival was the combination of nuclear area and nuclear elongation factor. CONCLUSIONS This study indicates that nuclear morphometry is prognostically superior to histological grade in patients with localized RCC.