Building on Shulman's (1986) theory of pedagogical content knowledge that outlines distinct domains of teacher knowledge, technological pedagogical content knowledge (TPACK) has emerged as a framework for examining educational technology training in teacher preparation (Koehler & Mishra, 2008; Neiss, 2008; Shin, Koehler, Mishra, Schmidt, Baran, & Thompson, 2009). The research presented here examines the theoretical basis of TPACK and describes the process of developing the Pre-service Teacher - Technological Pedagogical Content Knowledge Survey (PT-TPACK Survey). The PT-TPACK Survey is an instrument constructed to measure self-perceptions of TPACK in pre-service teachers completing a "Foundations of Educational Technology Course". The research focused on collecting evidence for the validity and reliability of the PT-TPACK survey. A pilot study, understandability study, and expert review were conducted in early stages of the research. Exploratory and confirmatory factor analysis and reliability measures were analyzed after the survey was administered to 120 pre-service teachers. The factor structure suggests a superior model fit, as did the goodness-of-fit indices. The root mean square error of approximation (RMSEA) was equal to .013, and both the comparative fit index (CFI) and non-normed fit index (NNFI) were ≥ .90 (CFI=1.0, NNFI=1.0). Internal consistency between the individual factors was also strong. The resulting coefficient alpha statistics suggest instrument reliability (TPACK, α=.903; TPK, α=.844; PK, α=.771; CK, α=.774; TK, α=.747; PCK, α=.653). Six of the seven widely accepted hypothesized TPACK dimensions emerged in the factor structure. Technological content knowledge (TCK) was the only hypothesized dimension that did not emerge. Finally, this study recommends several reasons for the lack of the TCK dimension, some of which could have an impact on how teachers are trained to use technology.