The treatment of chronic pain with opioids remains controversial. Physicians are concerned about addiction and drug diversion, and there is limited empirical information on the use of opioids in patients with chronic pain. This report presents data on the Addiction Severity Index (ASI) collected in a sample of patients (N = 908) receiving opioids from their primary care physicians. The ASI provides clinically important information about patients receiving opioid therapy. The ASI consists of seven subscales, including medical, alcohol, drug, employment/support, legal, family/social, and psychiatric domains. Clinically relevant findings include high ASI medical score (0.87), high psychiatric severity score (0.27), lifetime treatment of alcohol problems (reported by 22% of men), prior delirium tremens (5.6%), prior treatment for drug problems (10.1%), prior drug overdose (12.1%), and drunk-driving citations (28%); 40.3% of women had serious suicidal thoughts, and 23.8% had suicide attempts. The ASI provides important information that can help primary care physicians manage patients with chronic pain who are receiving opioid therapy.