Several unsuccessful attempts were made to produce sequels and remakes in the decades following Caligari's release. Robert Wiene bought the rights to Caligari from Universum Film AG in 1934 with the intention of filming a sound remake, which never materialized before Wiene's death in 1938. He intended to cast Jean Cocteau as Cesare, and a script, believed to be written by Wiene, indicated the Expressionist style would have been replaced with a French surrealist style. In 1944, Erich Pommer and Hans Janowitz each separately attempted to obtain the legal rights of the film, with hopes of making Hollywood remake. Pommer attempted to argue he had a better claim to the rights because the primary value of the original film came not from the writing, but "in the revolutionary way the picture was produced". However, both Janowitz and Pommer ran into complications related to the invalidity of Nazi law in the United States, and uncertainty over the legal rights of sound and silent films. Janowitz wrote a treatment for a remake, and in January 1945 was offered a minimum guarantee of $16,000 against five percent royalties for his rights to the original film for a sequel to be directed by Fritz Lang, but the project never came to fruition. Later, Janowitz planned a sequel called Caligari II, and unsuccessfully attempted to sell the property to a Hollywood producer for $30,000.
Around 1947, Hollywood agent Paul Kohner and German filmmaker Ernst Matray also planned a Caligari sequel; Matray and his wife Maria Solveg wrote a screenplay called The Return of Caligari. That script would have reimagined Dr. Caligari as a former Nazi officer and war criminal, but the film was never produced. In 1960, independent Hollywood producer Robert Lippert acquired the rights to Caligari from Matray and Universum Film AG for $50,000, and produced a film called The Cabinet of Caligari, which was released in 1962. Screenwriter Robert Bloch did not intend to write a Caligari remake, and in fact the title was forced upon his untitled screenplay by director Roger Kay. The film had few similarities to the original Caligari except for its title and a plot twist at the end, in which it is revealed the story was simply the delusion of the protagonist, who believed she was being held captive by a character named Caligari. Instead, he was her psychiatrist, and he cures her at the end of the film. In 1981, Bill Nelson was asked by the Yorkshire Actors Company to create a soundtrack for a stage adaptation of the film. That music was later recorded for his 1982 album Das Kabinet (The Cabinet Of Doctor Caligari).
A quasi-sequel, called Dr. Caligari, was released in 1989, directed by Stephen Sayadian and starring Madeleine Reynal as the granddaughter of the original Dr. Caligari, now running an asylum and performing bizarre hormonal experiments on its patients. The sex-driven story ultimately had little in common with the original film. In 1992, theatre director Peter Sellars released his only feature film, The Cabinet of Dr. Ramirez, an experimental film loosely based on Caligari. However, the storyline was created as the film was being made, so it has few similarities with the original film. The film was screened only at the 1992 Sundance Film Festival and never theatrically released. An independent film remake of Caligari edited, written and directed by David Lee Fisher was released in 2005, in which new actors were placed in front of the actual backdrops from the original film. The actors performed in front of a green screen, then their performances were superimposed in front of matte shots based on the original sets. Doug Jones played the role of Cesare.
Caligari was adapted into an opera in 1997 by composer John Moran. It premiered at the American Repertory Theater in Cambridge, Massachusetts, in a production by Robert McGrath. Numerous musicians have composed new musical scores to accompany the film. The Club Foot Orchestra premiered a score penned by ensemble founder and artistic director Richard Marriott in 1987. In 2000, the Israeli Electronica group TaaPet made several live performances of their soundtrack for the film around Israel. In 2014, Bertelsmann/BMG commissioned Timothy Brock to adapt his 1996 score for string orchestra for the new 2014 restoration, who conducted the premiere in Brussels on September 15, 2014. In 2012, the Chatterbox Audio Theatre recorded a live soundtrack, including dialogue, sound effects and music for Caligari, which was released on YouTube on October 30, 2013.
Deepan Sivaraman, noted scenographer and director from India, adapted the film into a hour long mixed media performance piece with the students of Performance Studies at Ambedkar University Delhi as a part of a course titled Space and Spectatorship. The performance took place in a run down warehouse on the university campus and employed multimedia projection to create visual impact. The show premiered in February 2015 at Delhi.