Screening for alcoholism and associated psychiatric disorders using preselected research criteria demonstrated an overall prevalence of alcoholism of 20% in 200 emergency department patients. The nighttime prevalence of alcoholism was 29%, while the daytime prevalence was 11%. The psychiatric disorders most frequently associated with alcoholism were primary affective disorder (depression) and antisocial personality. The alcoholics had chief complaints relating to trauma in 63% of the cases, vague neuropsychiatric complaints in 23% of the cases, and complaints directly related to alcohol in 8% of the cases. Screening for alcoholism and associated psychiatric illnesses is important in determining an overall treatment strategy for emergency patients.