The population studied included 427 MA-dependent men and women who entered treatment between 1988 and 1995 at the Matrix Institute on Addictions in San Bernardino County, California. The sample was divided into two groups according to their injecting status; 55 individuals (13 percent) reported injecting, and 372 (87 percent) reported no history of injecting MA. Data were compiled from an admission questionnaire that contained demographic information and drug, alcohol, medical, criminal, and psychological histories. Results showed that a majority of drug users experimented with various routes of administration throughout their drug careers. The group identified as injectors may have tried other routes but preferred and primarily employed needle use. The group identified as noninjection users varied their routes between smoking and sniffing, with sniffing being the primary route of administration. There seemed to be a stereotype present within the drug-using population that injectors were more dependent or more severe addicts than other users. Individuals who injected MA used it more frequently than noninjectors (on a daily basis), but the number of grams per week used did not differ between the two groups. Injectors reported more experiences of psychotic states and specifically more hallucinations and episodes of feeling that their body parts disconnected and left. In addition to more felonies, injectors were on parole more often than other users. Common felony charges for MA users were drug dealing, possession, and driving under the influence. Conversely, more noninjectors were on probation, suggesting lesser misdemeanor charges. 18 references and 1 table