Hospitalists practice hospital medicine, which represents the fastest growing medical speciality in the history of American medicine. Initially fueled by research demonstrating reductions in lengths of stay and hospital costs, the hospitalist movement has continued to gather momentum as a response to residency work hour revisions, patient flow challenges in hospitals, and a growing national focus on patient safety. Hospitalists have expanded the clinical services they provide to include coverage of the critically ill, palliative care, and surgical co-management. Hospitalists increasingly participate in nonclinical activities as well, including teaching, research, quality improvement, and clinical informatics. Challenges remain for this new field of medicine and present opportunities for research and innovation. Work life satisfaction may be enhanced by efforts to optimize workload and redesign care delivery models. Hospitalists may continue to demonstrate value to stakeholders by leading efforts to improve quality of care, especially in areas such as interdisciplinary communication and smoothing patients' transitions between care settings. Hospitalists should continue to take an active role in improving clinical efficiency and work with hospitals to fully leverage the capabilities of information and telecommunication systems. Looking to the future, hospitalists have exciting potential for a positive impact in a broad range of areas and lasting effect on healthcare delivery.