Case-based study has a lot of potential in supporting the success of learning outcomes needed in the 21st century, one of which is critical thinking skills. However, there are very few studies related to case-based study to promote critical thinking skills. Therefore, this study will analyze the effectiveness of case-based study in improving students' critical thinking skills. In this research, case-based study is carried out with engage, research, present (ERP) instructional model. The ERP model has potential and is in accordance with case-based study schemes for the university level. In addition, this study was also conducted to analyze the achievement of student independence in conducting research to solve a problem. This study used a non-equivalent control group research design with 70 samples divided into the experimental group (N = 35) and the control group (N = 35). The instrument used is a standardized test of critical thinking skills developed by Ennis, namely the Cornell Critical Thinking Test (CCTT) level X and an observation sheet for student independence in solving problems. The results showed that case-based learning using the ERP model (experimental group) was more effective than case-based learning without the ERP model (control group). However, the learning process carried out in groups is effective in improving critical thinking skills. This shows that case giving is quite effective in supporting critical thinking skills. In addition, the dominance of the achievement of student independence in conducting research (in the experimental group) to solve problems is at level 3, namely scaffolded research. The implication is that case-based learning is suitable for use in improving critical thinking skills at the university level.