Introduction: Team-based learning (TBL) engages students to participate in sharing knowledge and applications through teamwork. However, onsite learning was not possible during COVID-19 pandemic. This study aimed to assess the feasibility and effectiveness of online TBL as well as the effect of the learning method on performance and satisfaction of the students. Materials and Methods: An online TBL course was designed for the Hematopoietic System and Biology of Neoplasia module for 187 third-year medical students using both whole class and 'breakout rooms' feature of the Zoom^(TM) application. The individual and team readiness assurance tests (iRAT and tRAT) were conducted along with an application exercise. A 5-scale Likert-type questionnaire was used to explore the students' opinions. Results: Online TBL was done successfully. The 20-item tRAT median score was 17 (range 13-20), which was significantly higher than the iRAT median score of 9 (range 3-19) (p < 0.0001). The questionnaire response rate was 72% with a Cronbach coefficient of 0.898. It demonstrated satisfaction of the online TBL and confidence in using electronic technology for online learning. However, students seemed to feel that the quality of online learning was reduced. The favorable aspects included discussion with team members, application exercise practice, convenience, facilitators' roles, and teamwork. Conclusions: Online TBL was feasible as an online platform. It revealed high satisfaction, motivation of interactive learning, and development of interpersonal skills among medical students. Online TBL was used effectively during the COVID-19 pandemic to maintain interactive learning and the spirit of TBL.