Chronic opioid treatment is a highly effective method to treat chronic pain; however, the prevalence of abuse of opioids can make treating patients with these agents difficult for clinicians. The objective of this study was to describe rates of inappropriate utilization, abuse, and diversion in a population of patients who were prescribed chronic opioids, as measured by urine drug testing in the clinical setting. A retrospective analysis was conducted of results from all urine drug tests conducted by Ameritox, Ltd. between January 2006 and January 2009, for patients whose physicians ordered the test in order to screen for noncompliance. Data from 938,586 patient test samples showed that 75% of patients were unlikely to be taking their medications in a manner consistent with their prescribed pain regimen. Thirty-eight percent of patients were found to have no detectable level of their prescribed medication, 29% had a nonprescribed medication present, 27% had a drug level higher than expected, 15% had a drug level lower than expected, and 11% had illicit drugs detected in their urine. Note that all categories add to a total greater than 100% as each category is not mutually exclusive, and a single patient could fall into multiple categories. The high observed rate of noncompliance demonstrates a significant clinical concern and confirms the importance of periodic urine drug screening for the population prescribed long-term opioid therapy.