question: BACKGROUND: In the coronavirus disease-impacted era, many medical institutions have not permitted clinical practice at hospitals or have operated their training on a restricted basis. The effective strategy for improving therapeutic communication and team cooperation as a nursing core competency is required. OBJECTIVES: The study aimed to verify the effects of simulation problem-based learning on nursing students' communication skills, communication attitudes, and team efficacy. DESIGN: Non-equivalent control group pretest-posttest design. SETTINGS: A university in South Korea. PARTICIPANTS: Nursing students who were classified as advanced beginners were randomly allocated to the control group (n = 46) or the experimental group (n = 47). METHODS: The experimental group's students participated in the simulation problem-based learning for cesarean section maternity nursing. The control group's students participated in a conventional type of maternity nursing clinical practice. The communication skills, communication attitudes, and team efficacy were measured by using a self-reported questionnaire. RESULTS: As compared with the pretest, the communication attitudes increased significantly (t = 2.41, p = .020) in the posttest for the experimental group. The communication skills (t = 1.47, p = .150) and team efficacy (F = 3.30, p = .073) were not statistically significant. CONCLUSIONS: The simulation problem-based learning in clinical practice is recommended to improve communication attitudes for nursing students and to apply the learned knowledge in simulated nursing situations through experiential learning. Future research is particularly needed the standardized educational program to identify the long-term effects in various cases and settings.