This chapter shows how olfactory testing could be applied to investigations of orbitofrontal cortex (OFC) function and related behavioural outcomes. It discusses how tasks such as olfactory identification may offer insights into the development and maintenance of substance use disorders (SUD). Although imaging and neuropsychological studies demonstrate abnormalities in OFC function within addicted populations, it is unclear whether these deficits are related to premorbid vulnerability, a direct consequence of chronic exposure to addictive substances, or a combination of both. In humans, there is growing evidence that an earlier onset age of substance abuse may be related to more marked neurobiological and cognitive deficits. Adolescence is a developmental period associated with increased risk-taking and experimentation with drugs, and is also a time of increased vulnerability to the development of SUD. Experimentation with drugs also occurs during a period of substantial brain development and remodelling.