The Pharmacy and Therapeutics (P & T) Committee is an important medical staff advisory group. As the primary, formal communication link between the pharmacy and medical staff, the P & T Committee is of particular importance to the department of pharmacy services. All matters pertaining to the use of medications within the institution, including pharmacy programs, must be reviewed and approved through the committee. In addition, medication formulary data is reviewed through the committee and recommendations are offered to the medical staff. Such a wide diversification of involvement and activity necessitates the effective communication between all committee members. An active involvement in the committee by the department of pharmacy services is vital in order to develop a contemporary and progressive institutional pharmacy program. This series of four articles will address several important aspects of the committee's operation, including committee formation, mechanics, operation, and problem solving.