The appropriateness of pharmacist prescribing is examined, and limits that should be incorporated into legislation are discussed. Arguments that support pharmacist prescribing are that (1) in current practice, pharmacist consultation has evolved into prescribing; (2) there is a need for pharmacists to prescribe; (3) nurse practitioners and physicians' assistants, whose training in clinical pharmacology is conducted by pharmacists, have authority to prescribe in many states; (4) as the need for dispensing functions decreases, new functions must be assumed; and (5) pharmacist prescribing in pilot studies has been safe, effective, and either equal or superior to physician prescribing. Negative aspects of pharmacist prescribing include (1) not all pharmacists are competent to prescribe, (2) pharmacists are not trained in diagnosis, (3) physicians oppose it, (4) it could increase patient-care costs, and (5) pharmacists' access to patient information is not adequate for competent prescribing. Based on these arguments, legislation regulating pharmacist prescribing should contain certain limits: (1) certification to prescribe should be based on demonstrated competence, (2) pharmacists who prescribe must have access to medical records, (3) pharmacists must prescribe within established working relationships with physicians, and (4) pharmacist prescribing should be limited to long-term therapy for chronic disease and therapy for acute self-limiting illnesses that are not diagnostically complex. These limitations have been incorporated into California law. A bill is pending that allows pharmacists, within specified guidelines, to initiate drug treatment.