The relationship between onset of serious mental disorder and the occurrence of 37 crisis or stress events was studied as a potential focus for a preventive community program. Seven life-events occurring within one year prior to treatment were associated with serious mental disorder: being hospitalized for mental disorder, suicidal attempt, trouble with the police, onset of heavy drinking, loss of job, divorce/separation, and a family member beginning heavy drinking. None of these risk-markers were specifically related to diagnosis, though most markers were associated with alcoholism. Only two markers, divorce/separation and onset of drinking in a family member, tended to precede the onset of mental disorder. These markers may be useful as foci for a primary prevention program. A population-wide approach to prevention of major mental disorder awaits a clearer identification of factors which can be controlled.