The military provides a unique social environment given the organization and culture of the institution. Understanding substance use by those inside this institution provides insight into both the population as well as substance use in general. Using data collected from in-depth interviews, this article explores the nature and extent of substance use among a sample of current U.S. Army personnel. Additionally, possible interpretations of the cause of this substance use are explored and explained through the application of strain and social learning theories. Important findings include marijuana use (36% of sample) and steroid use (32% of sample). (Contains 7 tables and 1 footnote.)