This study reviewed selected treatment records of patients discharged from a drug treatment center. The research design was correlational comparing substance abuse diagnoses with relapse rates that had intensive outpatient therapy. The first group of reviewed records had a diagnosis of cocaine dependence (304.20) and received psycho-educational and individual/group cognitive behavioral treatment for sixteen (16) weeks. The second group of records reviewed had been diagnosed with poly-substance dependence (304.80) and received psycho-educational and individual/group cognitive behavioral treatment for sixteen (16) weeks. The hypothesis was that there would be a significant difference between relapse rates as defined by failed urinary drug screens for cocaine dependence (304.20) and poly-substance dependence (304.80) that have had a combination of psycho-educational/cognitive behavioral therapy. A point-biserial correlational coefficient was used. The independent variables were a diagnosis of cocaine dependence (304.20) and poly-substance dependence (304.80) and the dependent variable were defined as recorded in the patient's record as failed urinary drug screen. Results of the analysis determined the relationship between cocaine dependence (304.20) and poly-substance dependence (304.80) relapse rates. Results of the correlational analyses confirmed the hypothesis there was significant relationship between diagnosis type and relapse rates. More specifically, the direction of this relationship indicated that records that had a primary diagnosis of poly-substance dependence showed a greater rate of relapse as compared to the cocaine dependent group.