One of her best-known works is The Vintner's Luck (1998), which won several awards, has been published in ten languages,[1] and was made into a film of the same name by Niki Caro in 2009.

When she was sixteen, Knox's father overheard a discussion between her, her sisters, and Carol regarding the consequences of a secret treaty set in their imaginary world and remarked that he hoped they were writing this down.

[1] The novel is about the ghost of a World War I soldier, and it was inspired by a childhood memory; at age eleven Knox fell from a walnut tree on Anzac Day, and while in the hospital she overheard a conversation between an older man and her father about Passchendaele and life on the Salient in 1917.

[1] In 1988 Knox, Fergus Barrowman, Nigel Cox, and Damien Wilkins, with the help of Bill Manhire, Alan Preston and Andrew Mason, co-founded the literary journal Sport.

[3] Alongside these novels, Knox also wrote a trilogy of novellas based on her own experiences growing up in Wellington: Paremata (1989), Pomare (1994), and Tawa (1998),[3] later published in the compilation The High Jump: A New Zealand Childhood (2000).

[2] The Vintner's Luck won Knox widespread critical acclaim and numerous awards, and it raised her profile within New Zealand and overseas.

[24] Academic Erin Mercer notes that the novel reflects international Gothic and supernatural literary traditions as well as New Zealand fiction's more realistic approach.

[24] In 2002, Knox was appointed an Officer of the New Zealand Order of Merit in the 2002 Queen's Birthday and Golden Jubilee Honours, for services to literature.

[26][27] Jolisa Gracewood, reviewing Dreamquake, described the book as a "Mansfield-meets-Mahy fantasy" and praised Knox for her audacious imagination and ingeniously constructed tales.

[28] In 2008, she published a collection of non-fiction, The Love School: Personal Essays, which was shortlisted in the 2009 Montana New Zealand Book Awards.

[31] Knox was disappointed at the direction the movie took as she felt Caro "took out what the book was actually about", referring to the romantic relationship between Sobran and Xas which was a core aspect of the novel.

The Guardian said in its review: "Knox keeps the monster off stage and examines the psychological consequences of its depredations on the survivors, subverting the norms of the horror genre and thus making the ambiguous finale all the more startling.

"[40] The publication of both books in the same year caused some confusion, with New Zealand bookstore Whitcoulls inadvertently shelving Wake in the children's section and listing it as a "great gift for kids".