The aim of this study was to determine teachers' views on technological pedagogical content knowledge (TPACK), their self-efficacy, and whether these views changed according to sex, age, period of service, faculty graduated from, branch, access to the internet, the use of technology level, and access to in-service training which is oriented to the use of technology. Teachers' self-efficacies which are oriented to TPACK and its sub-dimensions known as technological knowledge (TK), content knowledge (CK), pedagogical knowledge (PK), pedagogical content knowledge (PCK), technological content knowledge (TCK) and technological pedagogical knowledge (TPK) were determined to be at a high level. According to this study, teachers' self-efficacy perceptions on TK, CK, PCK, TCK and TPACK did not change according to sex while the self-efficacy perceptions on PK and TPK changed according to sex. It was concluded that the self-efficacy perceptions of female teachers in these dimensions were higher when compared to those of male teachers. According to the present study, teachers' self-efficacy at TK and PCK changed according to age and the period of service, while self-efficacy at CK, PK, TCK, TPK and TPACK did not change according to these variables. In addition, a significant difference was determined between teachers' self-efficacy perceptions on TK and TPK according to the faculty graduated from. It was detected that the self-efficacy levels of classroom teachers on CK, TPACK, PCK and TCK were higher when compared with those of branch teachers. It was also concluded from this study that teachers' self-efficacy perception of TPACK did not change according to the situation of access to internet in the school in which they held office and that their efficacy was adequate. Teachers who thought that their self-efficacy in the use of internet was sufficient had higher levels of self-efficacies in TK, TCK, TKP and TPACK compared with other teachers. According to the present study, the in-service training that teachers receive on how to use the internet has more positive effects on CK and PCK compared with their self-efficacy in other dimensions.