The increasing incidence of illicit intravenous drug abuse has reached epidemic proportions in western society. Although the accompanying infectious complications such as hepatitis and acquired immunodeficiency syndrome receive the most notoriety, injection injuries are causing an increasing number of problems. A retrospective review of patients requiring admission for acute or chronic drug injection injuries of the upper extremities was made at the Detroit Receiving Hospital from 1980 through 1985. The demographical, historical, physical, microbiological, and follow-up data were analyzed. The majority of the injuries involved subcutaneous injections into the hand with accompanying inflammatory or infectious complications. The bacteriological data revealed unique characteristics and did not reflect patterns expected from inoculation of normal skin flora. A treatment regimen based on the data is proposed.