It starred Robert Young as the title character, a family practitioner with a kind bedside manner, who made house calls and was on a first-name basis with many of his patients; James Brolin as his partner Steven Kiley, a younger doctor; and Elena Verdugo as Consuelo Lopez, Welby and Kiley's dedicated and caring nurse/office manager.

The opening credits of each episode reminded viewers of the generation gap between the two doctors, Welby driving his sedan and Kiley riding a motorcycle.

Other characters that appeared throughout the series included Dr. Welby's frequent girlfriend Myra Sherwood (Anne Baxter), his daughter Sandy (originally Christine Belford, and later Anne Schedeen) and her son Phil (Gavin Brendan), and Kathleen Faverty (Sharon Gless), an assistant program director at the hospital, who worked closely with Welby and Kiley.

Kiley met and married public relations director Janet Blake (played by Pamela Hensley) in 1975, at the beginning of the show's final season on the air.

Story lines included impotence, depression, brain damage, breast cancer, mononucleosis, teenaged obesity, juvenile diabetes, sexually transmitted diseases, epilepsy, learning disabilities, leukemia, haemophilia, paraplegia, dysautonomia, rape, Alzheimer's disease, and addiction to painkillers, among others.

Members of the American Academy of Family Physicians served as technical advisers for the series and reviewed every script for medical accuracy.

[1] The next year, "The Outrage" was a story of a teenaged student who was sexually assaulted by his male teacher, associating homosexuality with pedophilia.

[4] In addition, an episode dealing with abortion was refused by San Diego area ABC affiliate XETV, a station licensed to Tijuana across the border in Mexico, due to that country's stance on the practice at the time.

In "Men Who Care", Marshall defends the father of Welby's patient when the man is accused of murdering his daughter's boyfriend.

Though Brolin was unavailable to reprise his role as Kiley, a statement described as being from him was read before the board that would decide Welby's fate.