We present 1 patient with hypouricemia and hyperuricosuria. Serum uric acid level ranged between 1.5 and 1.9 mg/dl and uric acid fractional excretion between 20 and 28%. Apart from that the renal function was normal. The pyrazinamide suppression test gave a normal response showing nearly complete suppression of urate excretion. The uricosuric response to sulfinpyrazone was normal too. The renal tubular response to extracellular fluid volume contraction induced by furosemide indicated a normal tubular sensitivity to extracellular fluid volume variations. From these results we conclude that our patient has a specific tubulopathy characterized by uric acid hypersecretion.