Medical Center (also known as Calling Dr. Gannon) is an American medical drama series that aired on CBS from 1969 to 1976. It was produced by MGM Television.

The show starred James Daly as Dr. Paul Lochner and Chad Everett as Dr. Joe Gannon, surgeons working in an otherwise unnamed university hospital in Los Angeles. The show focused both on the lives of the doctors and the patients showcased each week. At the core of the series was the tension between youth and experience, as seen between Drs. Lochner and Gannon. Besides his work as a surgeon, Gannon, because of his age, also worked as the head of the student health department at the university. Helping the doctors was the very efficient Nurse Eve Wilcox, played by Audrey Totter. She started out as a bit role, but was eventually upgraded to co‑star status starting in 1972. Wilcox became a regular after two other similar nurses (Nurse Chambers, played by Jayne Meadows; and Nurse Murphy played by Jane Dulo) had basically served the same functions as Wilcox.

• James Daly as Dr. Paul Lochner
• Chad Everett as Dr. Joe Gannon
• Chris Hutson as Nurse Courtland
• Virginia Hawkins as Nurse Evvie Canford
• Daniel Silver as Anesthesiologist
• Audrey Totter as Nurse Eve Wilcox
• Corinne Camacho as Dr. Jeanne Bartlett
• Eugene Peterson as Dr. Merrill Weller
• Ed Hall as Dr. Stan Bricker
• Jayne Meadows as Nurse Chambers
• Fred Holliday as Dr. Barnes
• Jane Adrian as Nurse Joyce Baxter

The show's Nielsen ratings are as follows:

Warner Bros. has released the seven seasons on DVD in Region 1 via their Warner Archive Collection. These are manufacture-on-demand releases, available exclusively through Warner's online store and Amazon.com.^{[2][3][4][5][6][7][8]}