The hospital has 136 beds and is affiliated with the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell.

[3] It was designed by East Meadow-based architect Siegmund Spiegel and built at a cost of $4.5 million (1962 USD).

[6][7] A major nurse's strike also occurred around that time that year, which temporarily closed the hospital.

[8] In 1995, Syosset Hospital became a member of North Shore Health Systems Inc (now Northwell Health)[9] and is a division of North Shore University Hospital[10] in Manhasset.

During the COVID-19 pandemic, nurses at the hospital protested Northwell's decision to extend the temporary closure of the hospital's psychiatric unit; Northwell temporarily closed it in order to house additional patients during the pandemic.