Importance: Despite decades of educational efforts, patients' prolonged delays in seeking care for symptoms of acute myocardial infarction (AMI) remain the greatest obstacle to successful management of the condition. Objective: To compare the effects of a narrative-based psychoeducational intervention with a didactic educative approach on AMI survivors' intention to seek care for AMI symptoms and on AMI knowledge. Design, Setting, and Participants: A multisite randomized clinical trial recruited community-dwelling patients aged 18 years or older with a history of AMI from 4 hospitals in Hong Kong from January 1, 2018, to January 22, 2021, and followed up participants for 1 year. Interventions: An 8-week narrative-based psychoeducational intervention aimed to create a vivid cognitive experience of complex decision-making and modeled desirable behavioral changes through nurse-led, interactive video sessions using model patients. The control group received 4 nurse-led sessions comprising education about AMI and care seeking delivered using a didactic approach. Main Outcomes and Measures: The primary outcome was the behavioral intention between the 2 groups, reflected by participants' attitudes and beliefs about care seeking for AMI measured using the Acute Coronary Syndrome Response Index-Chinese version. The secondary outcome was AMI knowledge. Results: Six hundred and eight participants (mean [SD] age, 67.2 [8.3] years; 469 [77.1%] male) were randomized to either the narrative-based psychoeducation group (n = 304) or the didactic education group (n = 304). The psychoeducational intervention group reported greater positive changes than the control group in their attitudes (ß = -1.053 [95% CI, -1.714 to -0.391]; P < .001) and beliefs (ß = -0.686 [95% CI, -1.354 to -0.180]; P = .04) toward care seeking at the 3-month follow-up, and the difference was sustained at 12 months for both attitudes (ß = -0.797 [95% CI, -1.477 to -0.117]; P = .02) and beliefs (ß = -0.692 [95% CI, -1.309 to -0.012]; P = .047). There were no significant differences in AMI knowledge between the 2 study groups at the 3-month and 12-month time points. Conclusions and Relevance: The results of this randomized clinical trial found that a novel approach of narrative-based psychoeducation was effective in improving patients' behavioral intention to seek care for AMI symptoms. Longer-term follow-up to evaluate actual care-seeking behavior and clinical outcomes in patients with AMI is warranted to determine the sustained effects of this intervention. Trial Registration: ChiCTR Identifier: ChiCTR-IIC-17010576.