A 37-year-old man with juvenile and refractory hypertension was admitted to our hospital for progressive left hearing loss, vertigo, and dizziness. Neurological examination revealed left hearing loss and exaggerated deep tendon reflexes and vestibular dysfunction. MRI and cerebral angiography disclosed megadolichobasilar artery (MDBA). Moreover, modified MR cisternography at the medulla disclosed marked compression and deformity of the left rostral ventrolateral medulla (RVLM) by the dolichoectatic right vertebral artery. In the literatures, bulbovascular compression has been reported in 4 among 9 patients with MDBA (including the present patient), for whom MRI of the medulla was presented. All 4 patients suffered from hypertension, and at least 3 of them showed juvenile and refractory hypertension. Ipsilateral pyramidal tract disturbance (Opalski syndrome) was observed in 3 patients. Considering the recent concept that the cardiovascular center can be localized at the RVLM, juvenile and refractory hypertension, and possibly Opalski syndrome in the present patient can be attributed to bulbovascular compression by MDBA. In the patients with MDBA and hypertension or Opalski syndrome, MR cisternography of the medulla is warranted to evaluate compression by MDBA.