In the Problem-Based Learning (PBL) model, students are expected to study independently. One of the methods that can improve the ability or skill of learners is using Computer Assisted Learning (CAL). Implementation of CAL in PBL should be able to create Self-Directed Learning (SDL) culture through appropriate instructional design and interesting modules. In this paper, the CAL software is developed using multimedia learning principles, convenient appearance, and user-friendly navigation. The CAL’s learning content is designed using Gagne's instructional design. The experiment proved the CAL was able to give effect size 0.89 and developed self-directed learning culture. From the interviews, students were very glad and interested to use the CAL modules because they can learn anytime and can reach the course objectives without a lecturer.