The Kitchen God's Wife tells the story of a Chinese-American family, alternating point of view between American-born Pearl and her immigrant mother, Winnie. The story starts with Pearl, her husband Phil, and her two young daughters, Tessa and Cleo, traveling to her hometown of San Francisco to attend her cousin Bao-Bao's engagement party. Once she arrives, her Auntie Helen uses her benign brain tumor to manipulate her and her mother into expressing their secrets to one another. She demands that Pearl tell her mother about her multiple sclerosis, and that Winnie tell her daughter the details of her life history, using lies about her imminent death to motivate them.
This is where the novel switches to Winnie's perspective, and begins describing Winnie's life story. She was born in China, abandoned by her mother as a child, and raised by unloving uncles. Her family forced her into an arranged marriage with a physically and emotionally abusive man named Wen Fu, and she had several children who died in infancy during the years of her marriage. Winnie managed to escape her marriage by fleeing China with Helen, and ended up marrying a man named Jimmy Louie. Pearl grew up believing Jimmy was her father, but Winnie reveals to her that she was actually conceived when Wen Fu raped her. After Winnie explains this history to Pearl, Pearl reveals her struggle with MS. The novel ends with Bao-Bao's wedding, and Helen, Pearl, and Winnie planning on visiting China together.