Purpose: Beta blocker (BB) has been prescribed for anxiety and panic disorder. Patients intoxicated by psychiatric drugs have often been exposed to BB. Moreover, BB overdose has adverse effects including cardiovascular effects, which can be life-threatening. This study was conducted to identify the characteristics of BB intoxication with psychiatric drugs and the adverse effects on the cardiovascular system. Methods: A single center, retrospective study was performed from January 2010 to December 2015. A total of 4,192 patients visited the emergency department (ED) with intoxication, and 69 with BB intoxication were enrolled. Results: Overall, 64 patients (92.8%) of enrolled patients were intoxicated with drugs prescribed for the purpose of psychiatric disorders. Propranolol was the most common BB (62 cases, 96.2%), and the median dose was 140.0 mg (25%-75% 80.0-260.0). Twenty-four patients (37.5%) had experienced cardiovascular events, and these patients tended to have decreased mentality, hypotension and coingestion with quetiapine. An initial mean arterial pressure (MAP) below 65 mmHg (odds ratio 10.069, 95% confidence interval 1.572-64.481, p=0.015) was identified as a factor of cardiovascular event upon multiple logistic regression analysis. Conclusion: Initial MAP below 65 mmHg was a factor of cardiovascular adverse effect in patients of BB intoxication with psychiatric drugs.