The purpose of this study was to adapt a survey developed by Chai, Jong et al. (2019) on technological pedagogical STEM (TP-STEM) knowledge into Turkish and to determine the knowledge of pre-service and in-service teachers about TP-STEM. The original survey consisted of four factors and a total of 17 items. These factors included Technological Pedagogical Knowledge in Science (TPSK), Technological Pedagogical Knowledge in Mathematics (TPMK), Technological Pedagogical Knowledge in Engineering (TPEK), and Integrative STEM (iSTEM) knowledge. The participants of the study were 520 pre-service and in-service teachers. The analysis showed that the model fit indices for the validity of the factor structures were acceptable with a value of RMSEA=0.0621 and showed excellent agreement with the values SRMR=0.0346, CFI =0.961, TLI=0.953. The Cronbach's alpha values for the factors ranged from 0.80 to 0.84 ([alpha]-value >0.70). These results mean that the survey adapted to Turkish language was reliable and valid for further research. The results showed that pre-service and in-service mathematics teachers had lower self-efficacy on the subfactors (TPSK, TPMK, TPEK, and iSTEM) than pre-service and in-service science and computer teachers.