The assessment of students' ability in gross anatomy is a complex process as it involves the measurement of multiple facets. In this work, the authors developed and introduced the Anatomy Competence Score (ACS), which incorporates the three domains of anatomy teaching and assessment namely: theoretical knowledge, practical 3D application of the knowledge, and clinical or bedside application of knowledge on patients. Equal contributions from these tripartite domains were used to synthesize the ACS. The theory knowledge was assessed using MCQs and short answer questions while the knowledge of practical 3D application was assessed using an Objective Structured Practical Examination (OSPE). The clinical or bedside application of anatomy knowledge was assessed by an Objective Structured Clinical Examination (OSCE). In this correlation study, the authors examined the interdomain correlations of the summative marks for the three contributing domains of the ACS, in order to examine the rationality of this new marker. Three cohorts of medical students (n = 538) at St. George's, University of London (SGUL) Medical School in the United Kingdom were included and analyzed. The results demonstrated that the correlations between the three domains were significantly low or moderate. The three domains probably represent unique knowledge and abilities. Therefore, it would appear that the average of the domains scores (the ACS) provide a comprehensive picture of a student's ability in anatomy.