Objective: The objective of this study was to determine treatment motivation and social support levels among patients with substance use disorders, the relationship between the variables, and influencing factors. Method: Descriptive research was conducted on 154 patients diagnosed with substance use disorder. The Individual Description Form, Treatment Motivation Questionnaire (TMQ) and Multidimensional Scale of Perceived Social Support (MSPSS) were used during data collection. Results: The mean score TMQ and MSPSS of the patients were determined as 93.44 +/- 10.03 and 44.85 +/- 13.74, respectively. Among the patients, the TMQ score of those who were in employment was higher than those who had previously made an attempt to stop using the substance (p < .05). The MSPSS score of men and employed patients was higher than that of women and unemployed people (p < .05). Conclusion: It was determined that participating individuals mostly used intrinsic motivation and that their treatment motivation and perceived social support levels were moderate. It was found that patients received the highest level of support from their families. As the level of social support increased, the patients' treatment motivation also increased. The study concluded that being in employment positively affected both social support levels and treatment motivation, while attempts to withdraw from the substance positively affected treatment motivation only.