Background: Simulation-based education has become an effective and widely used modern teaching method in health professional education. This approach allows students to apply theoretical knowledge into practice and develop essential skills such as clinical assessment, clinical decision-making, and teamwork in a safe and controlled learning environment. In recent years, international studies have demonstrated that simulation-based training improves students’ clinical skills, confidence, communication abilities, and professional attitudes. However, evidence regarding the effectiveness of simulation-based training remains limited in certain educational settings, particularly in developing countries. Therefore, evaluating the effectiveness of simulation-based training within local educational contexts is necessary. Aim: To evaluate the effectiveness of simulation-based training on students’ knowledge, clinical skills, and professional attitudes. Materials and Methods: This study included 45 third-year medical students from four classes at the Mongolian National University of Medical Sciences using a random sampling method. Participants were divided into two groups according to the training modality: a simulation-based training group (n=20) and a traditional learning control group (n=25). Knowledge was assessed before and after training using an 18-item test covering asthma etiology, pathophysiology, clinical features, diagnosis, and treatment. After the training session, students’ knowledge, clinical skills, and professional attitudes were evaluated using a 21item Likert-scale questionnaire and small-group discussions to identify factors influencing learning outcomes. The reliability of the questionnaire was evaluated using Cronbach’s alpha, which demonstrated high internal consistency (α=0.90). Statistical analysis was performed using SPSS software. Paired samples t-tests were used to compare pre- and post-training knowledge within groups, while independent samples t-tests were used to compare post-training outcomes between groups. Result: After training, mean knowledge scores significantly improved among all participants (pre-training: 9.18±2.33; post-training: 10.47±2.31; p<0.001). In the simulation group, knowledge scores increased from 7.65±2.01 to 9.05±2.46, while in the control group, scores increased from 10.40±1.80 to 11.60±1.41 (p=0.007). Post-training comparisons showed that the simulation group demonstrated higher mean scores in knowledge (36.70±3.73 vs 34.44±4.77) and clinical skills (11.35±1.69 vs 10.92±1.75) than the control group; however, these differences were not statistically significant (p>0.05). Professional attitude scores were significantly higher in the simulation group compared with the control group (43.35±3.60 vs 40.64±4.51, p=0.034). Conclusion Simulation-based training demonstrated positive effects on students’ knowledge and clinical skills and significantly improved professional attitudes. Integrating simulation-based training with traditional teaching methods may serve as an effective educational strategy to enhance the quality of clinical education.