The aim of this study is to determine the perceptions of primary school teachers related to the implementation levels of differentiated instruction, and to investigate these perceptions in terms of participating in in-service training for this approach, presence of students with different characteristic, graduated faculty, and gender. In the study, survey method as one of the quantitative research designs was employed. The study group of the research was composed of 703 primary school teachers selected by random sampling. The study data were gathered with "Differentiated Instruction Scale" developed by the researchers. The data gathered were subjected to descriptive and inferential statistics using the SPSS 18 software. As a result of the research, it was determined that the perceptions of primary school teachers related to the implementation of differentiated instruction were high. In addition, these perceptions of primary school teachers who participated in differentiated instruction training were significantly higher than those who did not, primary school teachers graduated from education faculties compared to those who graduated from other faculties, and female primary school teachers compared to men had higher perceptions of differentiated instruction. It was concluded that the perceptions of primary school teachers did not change significantly related to the presence of students with different characteristics in the classrooms. It is suggested that new studies should be carried out using the scale developed in this study and in-service training for differentiated instruction should be provided for teachers. [This article includes an extended summary in Turkish.]