Scientific reports are important tools for show results of experimental activities undertaken at undergraduate level. The aims of this research were detecting difficulties of undergraduate students in the elaboration of reports in the experimental chemistry subjects of students of the Science: Biology and Chemistry course at the Federal University of Amazonas in different periods (2nd to 10th). Results and discussion and theoretical bibliographic were topics reported with the most difficulty. The students showed little reading habit, however, which increases with the time they spend in university, also reflecting the retention rate in the experimental subjects. These results point to possibilities to reduce the difficulties in the elaboration of experimental reports by intervention alternatives more appropriate to the desired learning process, based on the students’ reality. Detecting these points becomes an important to assist them in the learning process of academic writing.