After Anne Frank's death was confirmed in the summer of 1945, her diary and papers were given to Otto Frank, Anne's father, by Miep Gies, who had rescued them from the ransacked hiding place. He left them unread for some time but eventually began transcribing them from Dutch for his relatives in Switzerland. He was persuaded that Anne's writing shed light into the experiences of many of those who suffered persecution under Nazis and was urged to consider publishing it. He typed out the diary papers into a single manuscript and edited out sections he thought too personal to his family or too mundane to be of interest to the general reader. The manuscript was read by Dutch historian Jan Romein, who reviewed it on 3 April 1946, for the Het Parool newspaper. This attracted the interest of Amsterdam's Contact Publishing, and in the summer of 1946, they accepted it for publication.
On 25 June 1947, the first Dutch edition of the diary was issued under the title Het Achterhuis (lit.: "the rear annexe"). Its success led to an English translation in 1952, which subsequently led to a theatrical dramatisation, and a cinematic version.
Otto Frank married a former neighbour from Amsterdam and fellow Auschwitz survivor, Elfriede Geiringer (1905–1998), in Amsterdam on 10 November 1953, and both moved to Basel, Switzerland, where he had family.
In response to a demolition order placed on the building in which Otto Frank and his family had hidden during the war, he and Johannes Kleiman helped establish The Anne Frank Foundation on 3 May 1957, with the principal aim of saving and restoring the building, to allow it to be opened to the general public. With the aid of public donations, the building (and its adjacent neighbour) was purchased by the Foundation. It opened as a museum (the Anne Frank House) on 3 May 1960, which can still be visited today.
Otto Frank died of lung cancer on 19 August, 1980.