Forty-nine patients with gout, many with hypertension and/or renal calculi, were given hydrochlorothiazide, furosemide, or ticrynafen. Diuresis and increased clearances of sodium (Na), potassium (K), chloride (Cl), and calcium (Ca) occurred after a single dose of hydrochlorothiazide, 100 mg, or furosemide, 40 mg, orally. There was very slight change in urate and phosphorus clearances. With prolonged use of hydrochloride or furosemide, diuresis and increased electrolyte excretion disappeared. Urate and Ca excretion fell with hydrochlorothiazide. With long-term use of furosemide, urate excretion was suppressed, but Ca excretion was sustained. Ticrynafen produced diuresis and increased clearances of Na, K, and Cl. Calcium excretion was increased after a single dose and minimally decreased after long-term use. Most striking was the severe and rather sustained uricosuria. Though ticrynafen is an effective uricosuric, natriuretic, and antihypertensive agent, its hepatotoxicity and nephrotoxicity mitigate against its clinical use.