Introduction: Pain is a common comorbidity among patients in substance abuse treatment. This study sought to assess the extent to which pain was endorsed as a reason for seeking admission to methadone maintenance. Methods: Cross-sectional survey of 5,803 individuals admitted to 69 US methadone maintenance treatment programs (MMTPs) between 1/05 -09/05. Respondents completed a structured, self-administered, 1 page questionnaire at intake. Pain (Non-withdrawal intensity) was measured on a 5-point scale (None – Very Severe). “Chronic pain” was defined as non-withdrawal pain of >moderate intensity and pain duration of >6 months. Generalized estimating equations (GEE) were used to examine associations between pain as a reason for enrollment and socio-demographic and drug-related variables; predictors with a p value of < 0.01 were reported. Results: 32.9% of study respondents endorsed pain as a reason for seeking enrollment in methadone maintenance. Of these, most were male (62.3%), Caucasian (65.7%) with a mean age of 37.2 years (SD ± 10.6). The primary drug of abuse within the past month was heroin (58.1%), or an opioid analgesic (41.9%). 69.3% reported experiencing severe or very severe withdrawal pain within the past week; and 63.8% reported severe or very severe bodily pain during that same period. Factors that were significant predictors of pain as a reason for enrollment in multivariate analyses included: having chronic pain (p<0.0001), being non-white (p<0.0001), being unemployed (p=0.006), methadone abuse within the past month (p=0.002), and, to have obtained their primary drug of abuse from a doctor's prescription (p=0.01). Conclusions: Methadone maintenance patients who cite pain as a reason for seeking substance abuse treatment are significantly likely to report having persistent bodily pain of moderate to severe intensity. They are also likely to have recently been abusing methadone, to be nonwhite and unemployed, and to obtain their primary drug of abuse through a prescription.