Purpose: This study aimed to develop and implement a multi-patient simulation (MPS) program for nursing students with no prior clinical practice experience. It also examined the effects of the program on the students’ communication competence and clinical reasoning ability. Methods: A one-group pretest-posttest design was used. The MPS program, consisting of four patient scenarios was applied to second-year nursing students with no prior clinical practice experience. Communication competence, clinical reasoning ability, and the perceived effectiveness of the multi-patient simulation program were measured using structured tools before and after the program. Results: Communication competence significantly improved after the MPS program, whereas clinical reasoning did not show a statistically significant difference. Perceived effectiveness of the MPS program was generally high, with the debriefing component scoring the highest. Confidence scores were relatively low, suggesting the need for level-appropriate scenario. Conclusion: The MPS program was effectively enhanced communication competence among preclinical nursing students. Although clinical reasoning scores did not improve significantly, the study highlights the importance of introducing realistic simulation experiences early in nursing education. Future research should focus on developing suitable clinical reasoning assessment tools for early year students and conducting randomized controlled trials to validate the effectiveness of customized MPS programs.