Kings County Hospital Center was founded 175 years ago, when Brooklyn was its own city and construction of the Brooklyn Bridge would not begin for almost 40 years. Over the decades, Kings County has claimed many "firsts" in the field of medicine: it was the site of the first open-heart surgery performed in New York State; Kings County physicians invented the world's first hemodialysis machine, conducted the first studies of HIV infection in women, and produced the first human images using magnetic resonance imaging (MRI). In addition, Kings County was named the first Level 1 Trauma Center in the U.S.

Kings County is in the midst of a $500 million rebuilding and modernization project, the largest in HHC’s history. The project was launched in 1997 and is scheduled for completion in 2009. Phase I saw the construction of the 340 inpatient-bed New Bed Tower, an inviting, patient-friendly environment equipped with the latest in medical technology. Phase II featured the completion of a state-of-the-art Emergency, Diagnostic and Treatment Pavilion. Phase III centered on the Ambulatory Care Center, a facility housing six stories of modern outpatient suites. Phase IV will bring a new Behavioral Health Center, while Phase V will encompass new facilities for hospital support departments; centralization of key services; demolition of vacated structures; fresh, campus-wide landscaping; and new parking structures.

An ongoing affiliation agreement between Kings County Hospital Center and SUNY-Downstate Medical School enhances the clinical, as well as the academic activities of both institutions.