This paper is based on the research question of what predictors (school characteristics, teachers’ attitudes, teacher collaboration and background characteristics) determine secondary school teachers’ frequency of computer use in class. The use of new technologies by secondary school teachers for educational purposes is an important factor regarding school and teaching processes. The use of digital media in schools is, among other things, associated with the goal of supporting learning processes and improving the quality of education. This contribution identifies relevant factors by means of multiple regression analyses of the teachers’ frequency of computer use for instruction in five countries (the Netherlands, Denmark, Australia, Poland and Germany) to get an idea of how to support the frequency of the use of computers in class. The analyses and findings are based on the International Association for the Evaluation of Educational Achievement (IEA) study of International Computer and Information Literacy Study 2013 (ICILS), which investigates the computer and information literacy (CIL) of secondary school students and the contexts in which students develop CIL in 21 countries. Antecedents concerning school characteristics, teachers’ attitudes and teacher collaboration on the process level and background characteristics of secondary school teachers (N = 8.920) are examined in order to gain further insight into the nature and effect of predictors for secondary school teachers’ in-class use of information and communications technology. The analyses show that there are more country-specific results than similarities between the countries selected. In all countries, antecedents concerning teachers’ attitudes are more relevant for teachers’ in-class use of computers than school characteristics or teacher collaboration on the process level.