The provision of pharmacokinetics services in Veterans Affairs (VA) medical centers was studied. In October 1992 a questionnaire was mailed to the chief of pharmacy at each of the nation's 160 VA medical centers. The survey was designed to determine the percentage of centers providing pharmacokinetics services, the general characteristics of pharmacokinetics services provided, and whether the presence of these services was associated with specific characteristics of the medical centers. Of the 160 questionnaires mailed, 148 (93%) were returned and analyzed. Pharmacokinetics services were provided by 104 (70%) of the respondents. Of the 104 services, 58 (56%) had existed for less than five years. Of the 44 VA medical centers without a pharmacokinetics service, almost two thirds planned to start one in the future. Aminoglycosides, vancomycin, and theophylline were the drugs most frequently monitored. Fifty-four percent of the pharmacokinetics services evaluated 1-24 patients per month, and another 24% evaluated 25-49 patients monthly. VA medical centers with a pharmacy residency program were more likely to have a pharmacokinetics service than centers without such a program; an association with geographic region was also identified. Nearly three fourths of responding VA medical centers indicated that they provided pharmacokinetics services.