Aniston, who has spoken publicly about her difficult relationship with Dow, confirmed the news of her mother's death on Wednesday to People in a statement. "It is with great sadness that my brother John and I announce the passing of our Mother Nancy Dow," she said. "She was 79 years old and passed peacefully surrounded by family and friends after enduring a long illness. We ask that our family’s privacy be respected as we grieve our loss."
Her mother had suffered strokes in 2011 and 2012, the site noted.
Dow appeared in the 1960s TV shows "The Beverly Hillbillies" and "The Wild Wild West," according to IMDb. After a previous marriage, she was married to Aniston's father, soap actor John Aniston, from 1965 to 1980.
Aniston's relationship with her mother reportedly soured in the 1990s and the rift intensified when Dow wrote a 1999 memoir From Mother and Daughter to Friends about Aniston.
The two were estranged for nearly a decade until reportedly reconnecting after Aniston's split from first husband Brad Pitt.
Aniston called Dow "critical" and "unforgiving" in a 2015 interview with The Hollywood Reporter, but she added, "We're all fine. "
This article has been updated following confirmation of when Nancy Dow died.