The United States Food and Drug Administration (FDA) has been warning about the psychiatric disorders associated with montelukast (MTK) for years. To study the characteristics of the presence of MTK-associated adverse events (AEs), we obtained data from the FDA Adverse Event Reporting System database and used a case (MTK) vs. non-case (all other drugs) analysis to investigate the safety signals in a disproportionality study. 27,507 reported AEs from January 2004 to December 2022 were analyzed. Disproportionality analysis shows that psychiatric, respiratory, thoracic, and mediastinal disorders as well as social circumstances are the most commonly reported AEs. In addition, our study found several unreported AEs, such as increased systolic blood pressure, diastolic dysfunction, hypothyroidism, obesity, bursitis, and polycystic ovaries. The timing of AE occurrence indicates that MTK-associated AEs are mainly acute effects. Most importantly, we found that 60.1% of patients reporting AEs in the category of psychiatric disorders were younger than 18 years. In summary, we revealed an age-preference pattern of psychiatric AEs in patients prescribed MTK. Our study is helpful for physicians and health professionals to better evaluate the value and risk of MTK and to achieve the goal of optimal patient care.