There is controversy over whether the use of montelukast increases neuropsychiatric events (NEs) in patients with asthma and allergic rhinitis. Our objective was to evaluate whether montelukast caused an increase in neuropsychiatric adverse reactions compared with placebo. We conducted a systematic review and meta-analysis to explore the relationship. The main result of the study was the incidence of NEs. Fifteen RCTs were screened and included for meta-analysis to merge statistics. The main results showed no significant increase in NEs compared with the placebo group. Similar results were seen in the occurrence of NEs in patients grouped by age and headache that the most common neuropsychiatric adverse event. Overall, montelukast did not significantly increase NEs in patients with AR and/or asthma compared with placebo.