Abstract: This paper reports a case of secondary hypertension caused by bladder paraganglioma coexisting with primary aldosteronism. A 60-year-old woman presented with a 9-year history of hypertension, characterized by marked post-micturition paroxysmal blood pressure elevation accompanied by headache and palpitations. Laboratory evaluation showed single-photon emission computed tomography (SPECT) significant post-micturition increases in plasma norepinephrine and normetanephrine levels. Aortic computed tomography angiography (CTA) revealed a nodule on the left posterior bladder wall, and ¹²³I-metaiodobenzylguanidine (MIBG) scintigraphy showed increased tracer uptake in the lesion. After adequate preoperative preparation, transurethral enucleation of the bladder tumor was performed, and postoperative histopathology confirmed bladder paraganglioma. The upright aldosterone-to-renin ratio was elevated, and confirmatory testing was positive, supporting the diagnosis of primary aldosteronism. Although CTA showed a unilateral adrenal nodule, adrenal venous sampling revealed no lateralized aldosterone secretion; therefore, medical conservative treatment was administered. After treatment, paroxysmal hypertension resolved, catecholamines and their metabolites normalized, and blood pressure remained well controlled at 3-month follow-up. This case highlights that in patients with paroxysmal hypertension triggered by specific precipitating factors, the coexistence of multiple causes of secondary hypertension should be considered.