She was twice married to Pulitzer-Prize winning writer William Saroyan over an eight-year period. The couple had two children: Aram Saroyan, an internationally known writer, and the late actress Lucy Saroyan, who died in 2003.

She also married actor Walter Matthau from August 21, 1959 until his death on July 1, 2000; they had one son, Charles Matthau. She had a wide social circle and was known for her wit and good company.

In 1955 she published a novella based on her experiences as a foster child, The Secret in the Daisy. In 1992 she published a memoir, Among the Porcupines.

Carol Saroyan Matthau died of a cerebral aneurysm on July 20, 2003, aged 78.