The anatomy of the first vertebra, namely atlas, has significant clinical implications. One of the clinically significant anatomical variants is the presence of an arcuate foramen. Arcuate foramen of atlas is an ossification of the oblique atlanto-occipital ligament superior to the vertebral artery groove of the atlas. The vertebral artery, which passes under these bony projections, can be compressed along with the suboccipital nerve causing a variety of symptoms. We present a series of anatomical case reports from a collection of 50 atlases with their analysis and brief review of their clinical significance. This anomaly is an underestimated structure, which is important to take into account in case of patients with a headache, vertigo, shoulder and arm pain, since in case of complete arcuate foramen, the number of symptomatic patients can be up to 78%.