Order sets provide straightforward clinical decision support within computerized provider order entry systems. They make "the right thing" easier to do because they are much faster than writing single orders; they deliver real-time, evidence-based prompts; they are easy to update; and they support coverage of multiple patient problems through linkages among order sets. This viewpoint paper discusses controversies surrounding use of order sets--advantages and pitfalls, decision-making criteria, and organizational considerations, including suggestions for vendors. Order sets have the potential to improve clinician efficiency, provide real-time guidance, facilitate compliance with Joint Commission on Accreditation of Healthcare Organizations and Centers for Medicare and Medicaid Services performance measure sets, and encourage overall acceptance of computerized provider order entry, but may not do so unless these controversies are addressed.