In 1976, Müller began working as a translator for an engineering factory, but was dismissed in 1979 for her refusal to cooperate with the Securitate, the Communist regime’s secret police. After her dismissal, she initially earned a living by teaching in kindergarten and giving private German lessons.

Müller’s first book, Niederungen (Nadirs), was published in Romania in German in 1982, in a state-censored version. The book was about a child’s view of the German-cultural Banat. Some members of the Banat Swabian community criticized Müller for “fouling her own nest” by her unsympathetic portrayal of village life. Müller was a member of Aktionsgruppe Banat, a group of German-speaking writers in Romania who supported freedom of speech over the censorship they faced under Nicolae Ceaușescu’s government, and her works, including The Land of Green Plums, deal with these issues. Radu Tinu, the Securitate officer in charge of her case, denies that she ever suffered any persecutions, a claim that is opposed by Müller’s own version of her (ongoing) persecution in an article in the German weekly Die Zeit in July 2009.

After being refused permission to emigrate to West Germany in 1985, Müller was finally allowed to leave along with her then-husband, novelist Richard Wagner, in 1987, and they settled in West Berlin, where both still live. In the following years, she accepted lectureships at universities in Germany and abroad. Müller was elected to membership in the Deutsche Akademie für Sprache und Dichtung in 1995, and other honorary positions followed. In 1997, she withdrew from the PEN centre of Germany in protest of its merger with the former German Democratic Republic branch. In July 2008, Müller sent a critical open letter to Horia-Roman Patapievici, president of the Romanian Cultural Institute in reaction to the moral and financial support given by the institute to two former informants of the Securitate participating at the Romanian-German Summer School.

The Passport, first published in Germany as Der Mensch ist ein großer Fasan auf der Welt in 1986, is, according to The Times Literary Supplement, couched in the strange code engendered by repression: indecipherable because there is nothing specific to decipher, it is candid, but somehow beside the point, redolent of things unsaid. From odd observations the villagers sometimes make (“Man is nothing but a pheasant in the world”), to chapters titled after unimportant props (“The Pot Hole”, “The Needle”), everything points to a strategy of displaced meaning … Every such incidence of misdirection is the whole book in miniature, for although Ceausescu is never mentioned, he is central to the story, and cannot be forgotten. The resulting sense that anything, indeed everything – whether spoken by the characters or described by the author – is potentially dense with tacit significance means this short novel expands in the mind to occupy an emotional space far beyond its size or the seeming simplicity of its story.”

In 2009, Müller enjoyed the greatest international success of her career. Her novel Atemschaukel (published in English The Hunger Angel) was nominated for the Deutscher Buchpreis (German Book Prize) and won the Franz Werfel Human Rights Award. In this book, Müller describes the journey of a young man to a gulag in the Soviet Union, the fate of many Germans in Transylvania after World War II. It was inspired by the experience of poet Oskar Pastior, whose memories she had made notes of, and also by what happened to her own mother.

In October 2009, the Swedish Academy announced its decision to award that year’s Nobel Prize in Literature to Müller “who, with the concentration of poetry and the frankness of prose, depicts the landscape of the dispossessed.” The academy compared Müller’s style and her use of German as a minority language with Franz Kafka and pointed out the influence of Kafka on Müller. The award coincided with the 20th anniversary of the fall of communism. Michael Krüger, head of Müller’s publishing house, said: “By giving the award to Herta Müller, who grew up in a German-speaking minority in Romania, the committee has recognized an author who refuses to let the inhumane side of life under communism be forgotten”

In 2012, Müller commented on the Nobel Prize for Mo Yan by saying that the Swedish Academy had apparently chosen an author who ‘celebrates censorship’.

Herta Müller wrote the foreword for the first publication of the poetry of Liu Xia, wife of the imprisoned Nobel Peace Prize recipient Liu Xiaobo, in 2015. Müller also translated and read a few of Liu Xia poems in 2014. On 4 December 2017, a photo of the letter to Herta Müller from Liu Xia in a form of poem was posted on Facebook by Chinese dissident Liao Yiwu, where Liu Xia said that she was going mad in her solitary life.

On July 6th, 2020 a no longer existing Twitter account published the fake news of Herta Müller’s death, which was immediately disclaimed by her publisher.