She was born in Samsun, in 1972 and lived in different parts of Turkey due to her father’s occupation. She had the chance to witness the cultural diversity of the country in her childhood years, which she spent both in big cities and rural areas. She completed her MA at the Faculty of Communication of Ankara's Gazi University in 1994 and moved to Istanbul. She presented her own arts show in the radio and published her short stories in the literary journal, Patika, when she was a student at the university. Her first short story collection received the Yaşar Nabi Nayır Youth Award, given by the prestigious literary journal, Varlık. She continued to publish her short stories in the journals such as Kitaplık, Adam Öykü and Düşler Öyküler. Her second short story collection received the Gençlik Publishing House Award in 1995.
Her first short story collection, Ortadan Yarısından was published in 1997. Her second book, Sandık Lekesi, which was published in 2000 and received the Cevdet Kudret Literature Prize in the same year, has become one of her most loved books by the readers and literary critics. Later on, she published two other short story collections, Doyma Noktası (2002) and Esir Sözler Kuyusu (2004). A compilation of her short stories was published under the title, Üşüyen/ Efsiri, as a bilingual edition in Turkish and Kurdish (2008). Her Öbür Yanım is a documentary work, which consists of her opinions on the beliefs of people in Turkey from different religions, communities and ethnicities. It also includes photographs by famous photographers (2007).
Her first novel, Yere Düşen Dualar was published in 2006. The book, which was welcomed by literary circles, was included in the list of “Best 10 Turkish Books that was Published in the Last 25 Years” by the newspaper Vatan. It was also included in the curricula of many Turkish Literature Departments. The novel was studied at the Turkish Literary Translation course of INALCO (National Institute of Oriental Languages and Civilizations), Paris, in 2007 and at “The Reflections of Modern Turkish on Literature” seminars at the University of Göttingen. It was also studied at the Department of Turkish Studies of the University of Hamburg in 2008.
The novel was published in German under the title, "Wein und Gold" in 2008 and in French as "La Chute des prières" in 2009. It received Ecrime Translation Award, France Turkey Award and Balkanika Award. It is also translated into Greek and Swedish.
She co-wrote the script of Yeşim Ustaoğlu’s film, Pandora’s Box with the director. The film received the best film award at San Sebastian International Film Festival. Kaygusuz was involved in the "Yakın Bakış" project of the Goethe Institute and was invited to Berlin in September 2008. She was one of the guest writers of "the eight writers’ exchange project" between Germany and Turkey. Her opinions on Berlin has been published by the Goethe Institute. She was also the leading name in the list, “Writers who will Leave Their Marks on Turkish Literature” prepared by the journal Notos through a public survey.
She received the Marguerite Yourcenar scholarship and completed her novel, Yüzünde Bir Yer at the Yourcenar Villa in Saint-Jans-Cappel, France in May/June 2009. The novel was inspired by the story of the writer’s grandmother who was a Dersim exile and it was honoured by Austria KulturKontakt. As a work on the Dersim Massacre, which had been a taboo subject, it was welcomed by the readers. Kaygusuz later recieved DAAD Berlin-Artists-In-Residence scholarship and lived in Berlin from April 2010 to April 2011.
Her short story, “Adak” (“Das Gelöbnis”) was included in the anthology Über Lebenskunst, which was published in August 2001. She stayed at the residence of KulturKontakt in September 2011 as a guest writer. She also stayed at the residence of MuzeQuarter from April 2012 to May 2012 as a guest writer. She has been organizing a creative reading and writing workshop at Bilgi University and Aralık Foundation since 2000. She occasionally writes for Notos.