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.
She subsequently married actor Walter Matthau on August 21, 1959. The couple remained wed until his death on July 1, 2000; they had one son, Charles. She had a wide social circle and was known for her wit and good company.
Carol Saroyan Matthau died of a cerebral aneurysm on July 21, 2003, aged 78. She was survived by her two sons and a sister, Elinor Dee Pruder.