Persons who inject drugs should use a new, sterile needle and syringe for each injection. Syringe exchange programs (SEPs) provide free sterile syringes and collect used syringes from injection-drug users (IDUs) to reduce transmission of bloodborne pathogens, including human immunodeficiency virus (HIV), hepatitis B virus, and hepatitis C virus (HCV). As of March 2009, a total of 184 SEPs were known to be operating in 36 states, the District of Columbia (DC), and Puerto Rico (North American Syringe Exchange Network [NASEN], unpublished data, 2009). Of these, 123 (67%) SEP directors participated in a mail/telephone survey conducted by NASEN and Beth Israel Medical Center (New York, New York) that covered program operations for the calendar year 2008. To characterize SEPs in the United States, this report summarizes the findings from that survey and compares them with previous SEP survey results from the period 1994-2007. In 2008, the 123 SEPs reported exchanging 29.1 million syringes and had budgets totaling $21.3 million, of which 79% came from state and local governments. Most of the SEPs reported offering preventive health and clinical services in addition to basic syringe exchange: 87% offered HIV counseling and testing, 65% offered hepatitis C counseling and testing, 55% offered sexually transmitted disease screening, and 31% offered tuberculosis screening; 89% provided referrals to substance abuse treatment. Providing comprehensive prevention services and referrals to IDUs, such as those offered by many SEPs, can help reduce the spread of bloodborne infections and should increase access to health care and substance abuse treatment, thus serving as an effective public health approach for this population.