Objectives: The Community Health Act came into effect in 1997 in Japan. This act altered the work system for public health nurses (PHNs) in public health centers (PHCs) nationwide from regionspecific to service-specific work. Such major changes to working environment in the new system seem to be exposing PHNs to various types of stress. The present study examined whether prevalence of burnout is higher among PHNs in charge of mental health services (psychiatric PHNs) than among PHNs in charge of other services (non-psychiatric PHNs), and whether attributes of emergency mental health care systems in communities are associated with increased prevalence of burnout.Methods: A questionnaire including the Pines burnout scale for measuring burnout was mailed to 525 psychiatric PHNs and 525 non-psychiatric PHNs. The 785 respondents included in the final analysis comprised 396 psychiatric PHNs and 389 non-psychiatric PHNs.Results: Prevalence of burnout was significantly higher for psychiatric PHNs (59.2%) than for non-psychiatric PHNs (51.5%). When prevalence of burnout in each group was analyzed in relation to question responses regarding emergency service and patient referral systems, prevalence of burnout for psychiatric PHNs displayed significant correlations to frequency of cases requiring overtime emergency services, difficulties referring patients, and a feeling of "restriction".Conclusions: Prevalence of burnout is high among psychiatric PHNs, and inadequate emergency mental health service systems contribute to burnout among these nurses. Countermeasures for preventing such burnout should be taken as soon as possible.