Although studies highlight the importance of note quality, most research on notetaking has traditionally focused on the quantity of words students produce. To address this gap, the present study investigates the effects of notetaking instruction on various dimensions of note quality and examines how these dimensions relate to the listening comprehension of 195 EFL learners at a Japanese university over one semester. Students received training in listening to academic lectures and taking notes using abbreviations and symbols. Each week, they listened to a short lecture, took notes, and answered comprehension questions in English. The lectures were carefully designed to ensure consistency in length, speech rate, lexical difficulty, topic diversity, and syntactic complexity. The first and final lectures served as pre- and post-tests to measure changes in notetaking and listening skills. Two trained raters (Cronbach's alpha = .90) assessed note organization and the inclusion of key and supporting information. All aspects showed substantial improvement following the instruction. Additionally, we analyzed which aspects of notetaking were associated with lecture comprehension, improvement, and EGAP listening performance, as measured by the TOEFL ITP®. The results showed that well-organized notes and the inclusion of main ideas and details were particularly important for listening comprehension. These findings suggest that teachers and researchers should place greater emphasis on the quality of student notes, and that students need to develop skills to effectively identify key information and organize it during lectures. • Multiple aspects of note quality improved after instruction and practice. • Note organization and the inclusion of main ideas and details were key predictors of listening success. • Note quality showed a stronger correlation with TOEFL ITP® listening scores than the total number of words. • The findings suggest that taking well-structured notes with sufficient details is more important than simply writing more.