Nigeria is currently witnessing an alarming increase in the rate of substance use and abuse among the youths and emerging adults. The disturbing phenomenon, undoubtedly constitute great threat to the entire society. Understanding the predisposing and perpetuating factors to substance abuse is crucial in stemming the tides of this menace. The present study is hospital-based aimed to explore factors influencing substance abuse among young individuals receiving treatment for substance use disorder in a tertiary hospital in Ogbomoso, Nigeria. Exploratory study was conducted among young individuals receiving treatment for substance use disorder in Ogbomoso, Nigeria. Twenty (20) purposively selected young adults (12 males, 8 females) receiving treatment for substance use disorder at Bowen University Teaching Hospital Ogbomoso, participated in three focus group discussions (male, female, and a mixed-gender groups), while two individuals were involved in separate in-depth interviews. Seven key themes (curiosity, peer pressure, enhance performance, boost self-esteem, cope with unpleasant emotions, frustration, and get high) emerged from the focus group discussions and in-depth interviews. It was concluded that the factors identified in this study should guide substance use disorder treatment development and implementation for improved outcome in Nigeria.