The purpose of this study is to investigate secondary and high school teacher perceptions about integrating educational computer games into their lessons. The participants consist of teachers who work at the 26 different secondary and high schools in Turkey. Two survey instruments were used to collect data from 581 participants. Data was analyzed using t-test, ANOVA test, Chi-square. Content analysis was also conducted to analyze the interview data. The findings revealed teachers who use educational games in their classes are more positive than the teachers who do not incorporate educational games in their lessons. Furthermore, secondary school teachers were more positive towards integrating educational games in their courses than high schools teachers. While teachers expressed their willing to use educational computer games in their courses, the negative aspects of computer games come to the fore according to the teacher perceptions.