At least ten percent of adults are diagnosed with Chronic Non-Cancer Pain (CNCP) every year and the associated costs are increasing. CNCP management is complex. Supplementation or substitution of the use of prescribed opioids with alcohol and marijuana is a major issue, especially among people of low-economic status or with a history of substance abuse. This project will analyze the beliefs and perceptions of CNCP patients treated in San Francisco safety net clinics about their experiences with pain and use and abuse of alcohol and marijuana.