Abstract Body (Do not enter title and authors here): Background: Due to the high passenger flow, train stations are at high risk sites for sudden cardiac arrest (SCA) occurrences. Recognizing the importance of early defibrillation and cardiopulmonary resuscitation (CPR) for survival, train stations are key locations for assessing public health interventions to improve SCA outcomes. Beginning progressively in 2019, train stations in one city implemented targeted personnel training and installed automated external defibrillators (AEDs). This study aimed to assess the effectiveness of these interventions. Methods: We prospectively collected all SCA events occurring in train stations (“close”) in one city and compared them with SCAs that occurred outside the home at locations more than 500 meters from any train station (“far”). Cases were divided into two temporal cohorts: a pre-intervention group (2015–2019) and a post-intervention group (2020–2023). Key outcomes—including bystander CPR, AED use, and survival rates—were compared between the “close” and “far” groups within each period using chi-square tests. Comparisons of survival rates were further quantified with odds ratio estimation and 95% confidence intervals (CIs). Results: Among 6,296 SCAs occurring in areas distant (“far”) from train stations, 1,225 patients survived, compared with 98 of 377 SCAs occurring near train stations (“close”). In the close group, bystander CPR rates were 80% in the pre-intervention period and 90% in the post-intervention period (p > 0.05). Similarly, in the far group, CPR rates increased from 74% to 84% (p > 0.05). AED use was significantly higher in the close group compared to the far group (p < 0.001), with rates increasing from 18% to 30% versus 7% to 11%. Survival rates were significantly higher in the close group than in the far group in the pre-intervention period (24% vs. 19%; p ≈ 0.04) and became even more pronounced in the post-intervention period (34% vs. 21%; p ≈ 0.009). Conclusion: These findings support the efficacy of targeted personnel training and the strategic placement of AEDs in public spaces. The significant improvements in AED use and the observed differences in survival underscore the potential benefits of such interventions in reducing SCA mortality.