A four-year-old girl presented in renal failure due to dihydroxyadenine urolithiasis. Prior to this she had been fed a high purine macrobiotic diet, rich in pulses and grain. She was comatose, anuric, requiring peritoneal dialysis, and bilateral radiolucent renal calculi were revealed by ultrasonography and retrograde pyelography. 2,8-dihydroxyadenine stones were found at pyelolithotomy, renal biopsy revealed interstitial birefringent crystals, and a complete lack of adenine phosphoribosyl transferase (APRT) was found subsequently in erythrocyte lysates. APRT levels were initially falsely raised due to a blood transfusion on admission. The mother was shown to have heterozygote levels. The child was treated successfully with allopurinol, and a reduction in dietary purine but with only partial return of renal function.