This study was carried out to determine the opinions of the pre-service primary teachers about the laboratory report writing in laboratory courses. Data were collected by using an open-ended questionnaire. The sampling of the study consists of 68 pre-service primary teachers who situated at a public university in the northeast of Turkey. Data were analyzed using content analysis. Two faculty members and one teacher jointly assessed the responses of the pre-service primary teachers to the questionnaire and determined the themes and codes for each question. The results showed that the pre-service primary teachers in the study paid attention to the content while writing laboratory report in the laboratory course. Also, they had positive and negative opinions about the contribution of laboratory report on their learning. Some of the preservice primary teachers stated that writing a laboratory report had positive effects such as providing learning, encouraging thinking, reinforcing what was learned, increasing interest and attention towards the lesson, and ensuring the permanence of the concepts learned. Some of the pre-service primary teachers thought that writing reports had a negative effect such as being boring and not contributing to the development of the individual. In addition, it was determined that performing a laboratory report reduced the students' interest in the course and pre-service primary teachers did not want to write a laboratory report. However, pre-service primary teachers accept that laboratory report increases their ability to comment.