Founded in 1890, it is the oldest hospital in San Diego County and has campuses in Chula Vista and Hillcrest.

[3][non-primary source needed] In 1890, the Sisters of Mercy opened a five-bed dispensary called St. Joseph's in downtown San Diego, with the permission of Bishop Francisco Mora y Borrell.

Even after it joining Scripps Health, it remains a Catholic hospital.

[9][additional citation(s) needed] In 2004, the two hospitals were combined at the Hillcrest campus.

[8][non-primary source needed] As recently as 2015, Nuns of Sisters of Mercy continue to work at the hospital, but fulfilling more spiritual needs rather than direct care.