Objective: To describe the general anatomical measures of atlas through the anatomical observation and by helicoidal computed tomography scanning of 30 samples of isolated Brazilian adult atlas. Methods: All the observed parameters were statistically analyzed. Results: The reproducibility was considered good for correlation coefficient > 0.80 which were achieved in twelve parameters measured. This was not true for measurements obtained for the intertransverse ligament distance and for the dimension of the odontoidal space. Conclusion: The data obtained will provide a better knowledge of the geometry dimensions of the atlas morphometry. The authors believe that those data may be contribute to the biomechanical and radiological studies as to the surgery of the craniocervical transition.