Measuring self-efficacy can be a valuable means for instructors to predict student performance. However, it is crucial to measure self-efficacy within specific contexts to effectively gauge students' perceptions of their capabilities. This study evaluated the factors comprising the Anatomical Self-Efficacy Instrument (ASEI) and determined whether these factors could predict performance in gross anatomy. Three cohorts of Doctor Physical Therapy (DPT) students completed the ASEI at the start of gross anatomy. An exploratory factor analysis (EFA) analyzed the ASEI's dimensionality, and Cronbach's alpha evaluated the internal consistency of the extracted factors. Linear regression was used to determine whether ASEI's total or subdomain scores predicted final anatomy course performance scores. In total, 142 of 287 (49.5%) DPT students completed the ASEI. EFA revealed three distinct factors, including "cognitive," "psychomotor," and "clinical anatomy self-efficacy", and explained 44.9%, 13.7%, and 5.2% of the total variance, respectively. Only cognitive self-efficacy predicted final gross anatomy course performance ([beta] = 0.34; R[superscript 2] = 0.071; F(3,138) = 3.51; p < 0.05). Overall, the ASEI's 3-factor solution implies its multidimensionality, a finding that could inform the development of more comprehensive self-efficacy measures. Notably, "cognitive self-efficacy" was the only subdomain that predicted DPT student performance in anatomy, suggesting its potential as a tool for identifying students in need of additional learning support. The ASEI's practical usability should be further explored through additional psychometric testing.