BACKGROUND: This study was constructed to detail the demographic and phenomenological features of pathological gamblers. METHOD: One hundred thirty-one subjects with DSM-IV pathological gambling were administered a semistructured interview to elicit demographic data and information on the phenomenology, age at onset, course, associated features, treatment history, and response to treatment of the disorder, followed by the Structured Clinical Interview for DSM-IV. RESULTS: Seventy-eight female (59.5%) and 53 male (40.5%) (mean +/- SD age = 47.7+/-11.0 years) pathological gamblers were studied. The majority of subjects (55.7%) were married. Subjects gambled a mean of 16 hours per week. Slot machines (65%), cards (33%), and blackjack (26%) were the most popular forms of gambling. The mean length of time between first gambling behavior and onset of pathological gambling was 6.3+/-8.9 years. Approximately one half (46%) of the subjects reported that television, radio, and billboard advertisements were a trigger to gamble. Most gamblers had severe financial, social, or legal problems. The majority of the subjects (58%) had at least 1 first-degree relative who also exhibited symptoms of problematic gambling behavior. CONCLUSION: Pathological gambling is a disabling disorder associated with high rates of social and legal difficulties.