This report reviewed 996 emergency room visits and 279 hospital admissions of patients with complications of cocaine abuse seen at the San Francisco General Hospital between 1979 and 1986. In 143 cases, acute neurologic or psychiatric symptoms were the primary complaint, and case-notes provided sufficient detail for analysis. The major neurologic complications included one or more seizures (n = 29), focal neurologic symptoms or signs (12), headache (10), and transient loss of consciousness (six). Psychiatric disturbances included agitation, anxiety, or depression (33), psychosis and paranoia (24), and suicidal ideation (18). The most serious consequences were found in patients with prolonged seizures or strokes, those who jumped out of buildings, and those who attempted suicide by overdosing with other drugs. There was no correlation between the appearance of complications and the reported route of administration, the amount of cocaine used, or prior experience with cocaine. The number of patients who are seeking hospital attention for these or related complaints appears to be rising substantially. Cocaine abuse, regardless of the use pattern, is associated with a variety of potentially severe neurologic and psychiatric complications.