Abstract. The purposes of this research was to find out how students’ need of guided discovery based chemistry module to improve critical thinking ability. This research was a qualitative study. The research population were XI grade IPA students in three schools. There were 107 students as samples of this research contained 38 students of XI IPA SMA Negeri 7 Pontianak, 37 students of XI IPA SMA Negeri 8 Pontianak, and 32 students of XI IPA SMA Negeri 9 Pontianak. This research used random sampling technique. Data gathering used non-test method by using open questionnaire with 19 questions. The results showed that 81.30% of students stated that the development of guided discovery based chemistry module are needed. Students stated that the guided discovery stages were guided them to study systematically, so the lessons are easier to understand. There are 79.43% students stated that guided discovery based chemistry module could helped them to think more critical. It is because to find a concept which is being learned, students have to use their thinking ability.

Keywords: module, guided discovery, critical thinking ability