Purpose: This study examined the effects of simulation-based education on knowledge about and self-confidence in maternity nursing care in senior students. Methods: One group, pre-post design, was utilized with 28 students. The simulation-based maternity nursing education that consisted of two sessions each 2 hours long for intrapartum and postpartum care was provided to 4 small groups. An expert panel of 3 maternity clinical instructors developed the module with a high-fidelity maternal simulator. Core items of knowledge about and self-confidence in maternity nursing care were measured with 13 items before and after the sessions. Results: The knowledge score did not increase significantly (z=-1.95, p=.05); however, self-confidence in maternity nursing care showed a significant change in the posttest (z=-2.82, p<.001). The subjective evaluation of the students indicated that the simulation-based education was helpful in preparing for clinical practicum as far as interaction with clients, psychological readiness to practice, and learning efficiencies. Conclusion: The simulation-based nursing education was useful in improving self-confidence in clinical performance for childbirth and postpartum care in nursing students. Along with the application of diverse scenarios in simulations, modules with standard patients and role-plays are also recommended for maternity nursing practicum to empower the competency of the students.