Mental health is becoming a central issue for public health complex emergencies. In this review we present a culturally valid mental health action plan based on scientific evidence that is capable of addressing the mental health effects of complex emergencies. A mental health system of primary care providers, traditional healers, and relief workers, if properly trained and supported, can provide cost-effective, good mental health care. This plan emphasises the need for standardised approaches to the assessment, monitoring, and outcome of all related activities. Crucial to the improvement of outcomes during crises and the availability to future emergencies of lessons learned from earlier crises is the regular dissemination of the results achieved with the action plan. A research agenda is included that should, in time, fill knowledge gaps and reduce the negative mental health effects of complex emergencies.