Solitary fibrous tumours are relatively rare neoplasms initially described in the pleura, Such lesions are now reported in many extrathoracic sites, To our knowledge, only 8 cases have been reported in the kidney, All these cases were benign. We report a patient with a solitary fibrous tumour of the kidney with infiltration of the wall of the renal vein, Microscopic examination showed proliferation of spindle cells with a prominent vascular haemangiopericytoma-like pattern. Hypercellular areas were admired with hyalinized collagenous zones. The neoplastic cells stained for vimentin and CD34, CD31 was negative, Biologically, we did not find any arguments for malignancy: the flow cytometric study showed diploid histograms, and immunostaining for p53 was negative, Copyright (C) 2000 S. Karger AG, Basel.