Purpose <p>To describe a case of right vertebral artery (VA) arising from the extreme proximal right subclavian artery (SA) and entering the C3 transverse foramen (TF), which was diagnosed by magnetic resonance angiography (MRA).</p> Methods <p>A 46-year-old woman with acute pontine infarction underwent MRA using a 3-Tesla scanner. MRA was performed using a standard 3-dimensional time-of-flight technique.</p> Results <p>MRA of the intracranial region revealed no pathological lesions. Fenestrations of the basilar artery were observed. MRA from the aortic arch (AA) to the craniovertebral junction level also showed no pathological lesions; however, there was a right VA arising from the extreme proximal right SA. The distance from the origin of the right SA to the origin of the right VA was 3&#xa0;mm. The right VA entered the C3 TF.</p> Conclusion <p>The right VA rarely enters C3 TF, with a reported prevalence of approximately 0.1%. The right VA arises from the right SA at two types of points: a normal point of origin and an extremely proximal point of origin. The latter type is considered to result from the same embryonic developmental variation of the left VA arising from AA. Although the image quality of MRA at the level of AA is not as good as that of computed tomography angiography, careful observation of MRA and the creation of reformatted MRA images are important for the correct diagnosis of this rare variation.</p>