OBJECT: The medial tubercles of the atlas serve as the attachments of the transverse ligament and provide an important anchoring site for which no discussion of their fine anatomy is published in the literature. In this study the authors examine this anatomy along with its osseous relationships. METHODS: One hundred dry cadaveric atlantal tubercles were assessed for size and relationship to nearby anatomical osseous structures. In addition, eight cadaveric specimens were evaluated for their anatomy in this area. All specimens exhibited atlantal tubercles for the attachment of the transverse portion of the cruciate ligament of the atlas. Right-sided tubercles tended to be of a larger caliber. Overall, right-sided vertical distances between these tubercles and the superior articular facets and inferior articular facets were greater, although distances from each tubercle to the lateral margin of the dental facets anteriorly were found to be constant, as were intertubercular distances. The mean angle formed between both tubercles and the dental facet was 75 degrees. CONCLUSIONS: The data derived in this study should be useful to the clinician for whom the craniocervical junction is a vital anatomical area.