Serum analysis of Vascular Endothelial Growth Factor (VEGF) and basic Fibroblast Growth Factor (b-FGF) levels were studied in 53 patients with renal cell carcinoma (RCC). Approximately 2/3 of the patients had disseminated disease at diagnosis, the remainder had no evidence of metastases. The results confirmed that VEGF has a major role in the angiogenesis of RCC. No correlation was observed between VEGF and/or b-FGF and the presence or absence of metastases, nor was any correlation observed between VEGF and/or b-FGF and patient survival. Thus, to utilise VEGF and/or b-FGF as a tumour marker at the time of diagnosis to predict patients with a high risk of progression, where an adjuvant therapeutic approach would be of great value, seems to be limited. Not all patients with RCC exhibited elevated serum levels of VEGF and/or b-FGF. No correlation was observed between tumour stage and serum levels of these angiogenic peptides.