A male patient undergoing hemodialysis in whom the cause of severe hyperkalemia (more than 8 mmol/liter) was found to be an unusual pica is described. His pica consisted of ingestion of burnt match heads (cautopyreiophagia). The potassium content of his daily consumption of burnt matches added 80 mmol to his 45 mmol dietary potassium intake. Hypogeusia and hypozincemia were documented. Oral zinc supplementation (zinc sulfate 220 mg per day for 10 weeks) normalized his plasma zinc level and taste acuity. He abandoned his pica and his plasma potassium level dropped significantly to 5.5 to 6 mmol/liter. It is suggested that inquiry about pica should be part of the dietary history in patients with renal failure.