Matrix‐metalloproteinases (MMPs) are associated with invasive and metastatic behavior of several human malignant tumors. We have determined MMP‐2 and MMP‐9 and tissue inhibitors of MMPs (TIMP‐1 and TIMP‐2) in blood plasma and in renal tissue samples of patients with renal cell carcinoma (RCC) from cancerous and non‐cancerous parts of the same kidney. In tumor tissue, MMP‐9 and TIMP‐1 were significantly higher than in normal counterparts. MMP‐2 was not different between tumor tissue and normal counterparts. TIMP‐2 values could not be measured. In plasma, MMP‐9 concentrations were significantly higher in RCC patients than in healthy controls, MMP‐2 and TIMP‐2 concentrations were higher in healthy controls and TIMP‐1 concentrations were not different. Int. J. Cancer 85:801–804, 2000. © 2000 Wiley‐Liss, Inc.