The effect of exposure to clinical pharmacists on physicians' favorability toward clinical pharmacy was studied. Questionnaires were sent to 576 physicians belonging to a county medical society. The survey measured the extent to which physicians agreed that hospital pharmacists should: (1) maintain drug profiles, (2) monitor prescribing patterns of physicians to preempt adverse reactions, (3) counsel patients at bedside, (4) decide on the frequency of use and dosage forms of physician-prescribed drugs, and (5) independently choose the drug to be prescribed based in the physician's diagnosis. A Guttman scale of task favorability was computed and compared four respondent groups: (1) physicians unaware of clinical tasks being practiced in hospitals, (2) physicians aware of clinical services but not knowing the clinical pharmacists, (3) physicians knowing the pharmacists but not working with them, and (4) physicians working with clinical pharmacists. There were 180 usable responses. While all groups were unfavorable to pharmacists independently choosing drugs, the physicians in groups exposed to pharmacists were favorable toward pharmacists counseling patients (p less than 0.001) and deciding on frequency of use and dosage forms of physician-prescribed drugs (p less than 0.05). More than 90% of the physicians working with clinical pharmacists ranked their quality of work as good or excellent. Exposure was related to specialty, risk of malpractice claim, and participation in hospital meetings. Exposure had a positive effect on the favorability of physicians toward clinical pharmacists and their services.