Self-efficacy and social support according to various researches have shown to be important factors in the initiation, recognition and enactment of behavioural changes. This study examines the influence of self-efficacy and social support on the intention to quit drug use among clients in some mental health settings and students in a university setting. The sampled participants in this study include 25 students of Ekiti State University, Nigeria and 60 patients drawn from different mental health settings. General self-efficacy scale was used to measure self-efficacy while multi-dimensional social support scale was used to measure social support. Intention to quit drug use was measured using the Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES). The result shows that there is a significant difference between drug abusers in a mental health setting and drug abusers in a university setting on all the three dimensions of intention to quit drug use; the patients having a higher score on the three. The three dimensions of social support do not have a significant influence on intention to quit drugs while Self-efficacy has a major influence on the intention to quit drug use (Beta = .244, P<.05). From the research findings, individual characteristics like self-efficacy play a major role in therapy and on patients’ intention to quit drugs than social support but this does not negate the importance of social support in therapy. So, therapists should endeavour to assess and develop an individual's attitude to prevent relapse after treatment. More so, psycho-education is pivotal in drug use cessation when compared with the population that was not exposed to psycho-education. So, awareness about the dangers of drug abuse should not only be done in mental health settings; but also in schools and our society at large.