-The hospitalist movement represents a novel paradigm of health care delivery in the USA, its evolution hastened by a variety of financial, clinical, and time pressures. Hospitalists are site-defined specialists who spend the majority of their professional time practising in the hospital, and in this respect are similar to emergency medicine or critical care specialists. Community hospitals were the sites of early growth in hospitalist systems, and academic medical centres quickly followed suit. The field has grown rapidly, and now has its own textbook, professional society, training programme, and research and educational agenda. Published research to date has upheld the promise of the hospitalist model: improving efficiency of care by reducing length of stay and hospital costs without compromising quality or patient satisfaction. Future hospitalist research will aim to elucidate the role of hospitalists in the care of critically ill and surgical patients, identify the competencies that will ultimately define this specialty, and expand our understanding of key inpatient issues, such as prevention of nosocomial infections, end-of-life care, and hospital quality measurement. KEY WORDS: hospitalists, job satisfaction, medical specialties, organisational models, outcome and process assessment, patient satisfaction A novel health care paradigm First coined in 1996, the term 'hospitalist' described a new breed of physicians in the USA who focused on the care of medical inpatients 1 . Traditional models of health care delivery in the USA place the primary care physician -a general internist, paediatrician, or family physician -as the physician of record for most non-surgical hospitalised patients, receiving assistance from subspecialists as the need arises. In a hospitalist system, primary care physicians transfer the responsibility for hospital care to an inpatient specialist, whose expertise is defined not by an organ system but by site of practice. The hospitalist then refers the patients back to their primary care physician at the time of discharge. Although a generation ago American primary care physicians spent nearly half their time providing hospital care, they now spend an average of 12% of their time in the hospital 2 .Many influences hastened the evolution of a novel paradigm of health care delivery in the hospital: time constraints on the primary care provider; fewer inpatients for individual primary care physicians; cost pressures on the hospital and medical groups with reduced rates of reimbursement for inpatient services; the heightened acuity of medical inpatients; the accelerated pace of inpatient care; and the evidence that 'practice-makes-perfect' in other medical fields 1 .Originally defined as physicians who spend more than 25% of their time caring for inpatients 3 , the first American hospitalists grew out of a cohort of generalists and specialists already performing the majority of their clinical duties in the hospital. The 1997 survey from the National Association of Inpatient Physicia...