Radiation-induced renal artery stenosis has only rarely been described in the literature, but arterial hypertension due to radiation-induced renal artery stenosis is a serious long-term sequela that can appear at a latency of up to 20 years after treatment. The paucity of reports presumably reflects the lesser frequency of radiotherapy for retroperitoneal tumors as compared to head-and-neck cancers, as well as lower awareness of the problem due to diagnostic bias in the era before CT and MRI were in routine use: at that time, carotid artery stenosis was easy to diagnose by ultrasonography, while radiation-induced renal artery stenosis, whose real incidence may well be higher, probably often went undetected. Thus, when a patient with a history of abdominal or retroperitoneal radiotherapy unexpectedly develops intractable hypertension, radiation-induced renal artery stenosis must be included in the differential diagnosis.