The purpose of the study is to investigate the opinions of classroom teachers and students and who write letter-summary and posters as a learning writing activity for the unit of Let's Know the Matter in the fourth grade science lesson. In the study, one of the qualitative research methods, the opinion form approach was used. The data of the study were obtained by using the student and teacher opinion form with open-ended questions prepared by the researcher in line with the expert opinion. The data obtained from the participants were analyzed by content analysis technique. The findings of the study indicated that students and teachers showed a positive approach towards learning writing activities. As a result of the study, it was observed that students liked writing activities for learning purposes and wanted to repeat them, and teachers believed in the benefits of the activities but did not have enough information about the activities.