The objective of the research is to identify the level of Technological pedagogical and content knowledge of Chilean teachers in service and its relationship with demographic variables. Information was collected from 214 teachers from Provincia de Elqui (Chile) applying a questionnaire of knowledge of the seven dimensions of the TPACK, and demographic variables. It is concluded that the levels of knowledge of the dimensions associated with ICT are lower than those associated with content and pedagogic. Age, gender, ICT training, time of use, type and frequency of use can be related to different levels of development only in some of the TPACK dimensions.