23.61% of homeless youth (n = 1046) reported non-medical use of prescription drugs (NMUPD).
Significant associations were found between perceived network norms (descriptive and injunctive) and NMUPD among this at-risk population.
The associations between network norms and NMUPD varied by network type.
Findings also indicate associations between other drug use (marijuana, heroin and injection drug use) and NMUPD.
Interventions designed to target social network norms of NMUPD might be a viable strategy to reduce NMUPD among homeless youth.