The Accreditation Council on Graduate Medical Education (ACGME) requires that house officers demonstrate competencies in "practice-based learning and improvement" and in "the ability to effectively call on system resources to provide care that is of optimum value." Anticipating this requirement, faculty at a Boston teaching hospital developed a 3-week elective for medical house officers in quality improvement (QI). The objectives of the elective were to enhance residents' understanding of QI concepts, their familiarity with the hospital's QI infrastructure, and to gain practical experience with root-cause analysis and QI initiatives. Learners participated in three didactic seminars, joined hospital-based QI activities, conducted a root-cause analysis, and completed a QI project under the guidance of a faculty mentor. The elective enrolled 26 residents in 3 years. Sixty-three percent of resident respondents said that the elective increased their understanding of QI in health care; 88% better understood QI in their own institution.