Objectives: To determine the effectiveness of self-directed, case-based learning in cancer pain management via a digital learning platform (e-CBL) in interdisciplinary residents' knowledge and critical thinking skill level. Methods: The prospective observational study was conducted on 51 first-and second-year residents from anesthesiology, surgery, and family medicine who had not received training in the management of cancer pain and were invited to participate by their Program Director. Participants voluntarily underwent e-CBL in cancer pain management using four modules (pain assessment, principles of pain management, pharmacological techniques, and non-pharmacological techniques) at their convenience within seven days via the Moodle platform. All participants underwent pre-and post-test assessments of knowledge and rated their satisfaction with the training on a 0-10 scale. Thirty-two residents completed Cornell Critical Thinking Test Level Z. Paired t-tests assessed changes, and the effect size was estimated by Cohen's d. A p-value < .05 was considered statistically significant.Results: Knowledge and critical thinking test results significantly improved after the training (M=68, SD=16.99 to M=86, SD=13.96 correct responses; t(50)=11.24, p<.001, Cohen's d=1.56 for knowledge) and (M=39.8, SD=13.7 vs. M=46.1, SD=10.2 correct responses; t(31)=-3.67, p=.001, Cohen's d=0.65 for critical thinking test). Satisfaction of learning experiences for convenience and understandability was high (M=9.4, SD=0.8).Conclusions: Use of the e-CBL improved knowledge in cancer pain management and critical thinking skills. This digital platform could play an important role in the future of pain education. Further investigation, including a control group, is warranted.