Provision of drug information services to both health professionals and consumers is described. The Rocky Mountain Drug Consultation Center (RMDCC) has been available to health professionals at Denver General Hospital since 1977. In April 1979, the RMDCC began promotion of combined health-professional- and consumer-oriented services. The service operates 8 a.m. to 6 p.m., Monday through Friday, with 24-hour on-call service. It is staffed by pharmacists who devote 70 man-hours per week to it. Training is primarily on the job. Most of the $80,500 budget is funded through a public health grant from the State of Colorado. a nine-member physician advisory board periodically reviews quality of responses. During a one-year period (April 1979-March 1980), 2264 calls were received from consumers and 1762 calls from health professionals--an increase of 197% over the previous year. Approximately 90% of consumer calls were not considered serious problems or were informational requests; 10% were considered potentially serious or serious drug-related problems. Less than 1% of consumers' questions required the use of anything more than basic drug information references. Of 76 follow-up calls made to consumers for serious or potentially serious problems, 73 were successfully recontacted, and 70 said they either followed RMDCC's recommendations or contacted their physician. The authors believe that combined consumer-oriented and health-professional-oriented drug information services help prevent misuse of medications by consumers.