This study examined the factor structure of the Teachers' Sense of Efficacy Scale (TSES; Tschannen-Moran & Woolfolk Hoy, 2001) using the scores of pre-service teachers at the beginning stage of teacher development to gather internal structure score validity evidence. Two plausible rival models derived from prior research were tested using CFA. Results showed good fit for both models; however, high inter-factor correlations indicate strong support for the unidimensional model. Findings suggest that pre-service teachers who lack pedagogical knowledge and teaching experience do not differentiate between the different aspects of teaching measured by the TSES. Questions for future research are raised. (Contains 4 tables.)