We report here a unique case of recurrent malignant hypertension after the removal of an adrenal tumor for primary aldosteronism. The patient had a history of hypertension for 15 years. In 1995, he developed drug-resistant hypertension with hyperreninemia, hyperaldosteronemia and hypokalemia. He was diagnosed as having primary aldosteronism with a right adrenal tumor. His blood pressure did not normalize and renal dysfunction continued after the adrenalectomy. Although antihypertensive treatment was continued for residual hypertension, he soon refused medication. In 1997, he developed recurrent malignant hypertension. It was considered that the different underlying mechanisms might be attributable to the two episodes of malignant hypertension in this patient.