Self-efficacy is defined as a person's beliefs in his or her own abilities to successfully complete a task and has been shown to influence student motivation and academic behaviors. More specifically, anatomical self-efficacy is defined as an individual's judgment of his or her ability to successfully complete tasks related to the anatomy curriculum; these include dissecting, learning anatomical concepts, and applying anatomical knowledge to clinical situations. The purpose of this study was to investigate the influence of anatomical self-efficacy on the academic performance of students enrolled in a medical gross anatomy course. To obtain students' anatomical self-efficacy ratings, surveys containing the same anatomical self-efficacy instrument were completed by first-year medical students at a southeastern United States allopathic medical school after each of four gross anatomy assessments. Additional data collected included student demographic information, Medical College Admission Test® (MCAT®) scores, and anatomy assessment scores, both written examination and laboratory practical. To investigate the potential predictive nature of self-efficacy for academic performance on both the written examination and the laboratory practical components of medical anatomy assessments, hierarchical linear regression analyses were conducted. For these analyses, academic ability (defined as the sum of the physical sciences and biological sciences MCAT scores) was controlled. The results of the hierarchical linear regressions indicated that all four laboratory practical scores were predicted by the corresponding self-efficacy ratings, while two (i.e., thorax/abdomen and pelvis/lower limb) of the four written examination scores were predicted by the corresponding self-efficacy ratings (P ≤ 0.05). Anat Sci Educ. © 2012 American Association of Anatomists.