Introduction: Continuing medical education (CME) courses are an essential component of professional development. Research indicates a continued need for understanding how and why physicians select certain CME courses, as well as the differences between CME course takers and nontakers. Purpose: Obstetrician-gynecologists (OB-GYNs) are health care providers for women, and part of their purview includes mental health, such as postpartum depression (PPD) and psychosis (PPP). This study evaluated OB-GYNs' knowledge, attitudes, and behavior (KAB) regarding PPD/PPP, and compared characteristics of CME course takers and nontakers. Method: A survey was sent to 400 OB-GYNs. Results: Response rate was 56%. One-third had taken a CME course on PPD/PPP. Those who consider themselves a "specialist" were less likely to have taken a CME course on postpartum mental health than those who consider themselves "both primary care provider and specialist." Non-CME course takers rely on clinical judgment more. They also are less likely to track patients' psychiatric histories and they utilize validated assessments less frequently. However, CME course takers and nontakers did not differ on knowledge or belief items. Conclusion: CME courses on PPD/PPP were associated with increased screening and utilization of validated assessments. There was no association between having taken a course and several knowledge questions. It is unclear if CME courses are effective in disseminating information and altering KAB. (Contains 3 tables and 1 figure.)