Computerized prescribing in the practice of medicine is a change that is overdue. Virtually all prescriptions in the United States are still handwritten. Instead, medications should be ordered on a computer interacting with 3 databases: patient drug history, scientific drug information and guideline reference, and patient-specific (weight, laboratory) data. Current problems with prescribing on which computerized prescribing could have a positive impact include (1) drug selection; (2) patient role in pharmacotherapy risk-benefit decision making; (3) screening for interactions (drug-drug, drug-laboratory, drug-disease); (4) linkages between laboratory and pharmacy; (5) dosing calculations and scheduling; (6) coordination between team members, particularly concerning patient education; (7) monitoring and documenting adverse effects; and (8) postmarketing surveillance of therapy outcomes. Computerized prescribing is an important component of clinician order entry. Development of this tool has been impeded by a number of conceptual, implementation, and policy barriers. Overcoming these constraints will require clinically and professionally guided vision and leadership.