Primary aldosteronism is a potentially curable cause of hypertension, especially when caused by an adrenal adenoma. Aldosteronomas because of their small size often elude techniques to locate them. This case illustrates the advantages, disadvantages and complications of noninvasive techniques used for their diagnosis. A patient with hypertension and hypokalemia underwent an adrenal venous effluent sampling for measurement of aldosterone concentrations. This procedure was complicated by an injury to the right adrenal gland. Subsequently, it was difficult to control the patient's hypertension and hypokalemia with medical therapy alone. A re-assessment years after his initial diagnosis included a CT scan, which now visualized a left adrenal tumor. The functional status of this tumor and lack of function of the previously injured right adrenal gland were demonstrated by NP-59 scintigraphy. This information modified the surgical intervention (adenectomy rather than total adrenalectomy) and the residual left sided adrenal tissue prevented adrenocortical insufficiency. A year later the patient remains euadrenal.