Background and Aims: Despite evidence that COVID-19 vaccination can strengthen mental health, there is limited evidence about this in Bangladesh. Thus, this comparative study assessed the prevalence and factors associated with mental health problems between vaccine receivers and nonreceivers.Methods: Using a snowball sampling technique, a web-based cross-sectional study was conducted among a total of 459 participants. The survey questionnaire included sociodemographic information, the Patient Health Questionnaire (PHQ-9), the Generalized Anxiety Disorder (GAD-7), and the Trauma Screening Questionnaire (TSQ-10).Results: The study found that mental health problems were nonsignificantly prevalent in the vaccine nonreceivers than those who received it (i.e., 24.79% vs. 20.60% for depression, 21.20% vs. 16.60% for anxiety, and 15.30% vs. 12.60% for posttraumatic stress disorder). Female gender, chronic condition, smoking status, and alcohol consumption were the risk factors for mental health problems.Conclusion: This study's findings suggest that the COVID-19 vaccination necessarily improves mental health outcomes. However, the study had limitations in terms of its design and sampling technique, and further research is needed to establish a causeeffect relationship between vaccination and mental health problems.