An unabridged The Man in the High Castle audiobook, read by George Guidall and running approximately 9.5 hours over 7 audio cassettes, was released in 1997. Another unabridged audiobook version was released in 2008 by Blackstone Audio, read by Tom Weiner and running approximately 8.5 hours over 7 CDs. A third unabridged audiobook recording was released in 2014 by Brilliance Audio, read by Jeff Cummings with a running time of 9:58.
After a number of attempts to adapt the book to the screen, Amazon's film production unit began in October 2014 filming the pilot episode of The Man in the High Castle in Roslyn, Washington, for a new television drama to air on the Amazon Prime web video streaming service. The pilot episode was released by Amazon Studios on January 15, 2015, and was Amazon's "most watched pilot ever" according to Amazon Studios' vice president, Roy Price. On February 18, 2015, Amazon green-lit the series. The show became available for streaming on November 20, 2015.
The television series diverges from the novel in many significant respects. Both the Pacific States of America and the Eastern American puppet state appear to be mere provinces of the Japanese and German empires without any apparent autonomous (even quisling) government institutions whatsoever. The Rocky Mountain States become a literally (and implausibly) anarchic Neutral Zone. World War II appears to have ended following the destruction of Washington, D.C. with an A-bomb, rather than a land invasion as in the book. As for Hitler himself, while elderly, he is apparently mostly hale in his Season 1 finale appearance, though other characters elsewhere in the season do reference his supposed physical infirmity. In the novel, the Italian Empire is a minor power which controls North Africa and the Middle East; in the series, however, it is shown through maps that these territories are part of the Nazi Empire, suggesting that either the Italian Empire was annexed after the war or is self-governing within the Reich.
Characters from the book that do appear are in most cases far more fleshed out with deeper and sometimes rather different backstories than their novel originals. For instance Wegener is a standartenführer in the SS rather than a naval captain (and oddly there are no German military or naval – as opposed to SS – personnel depicted anywhere in the first season). Rather than being a member of an organized internal resistance (and despite his relatively low rank) Wegener is a close personal confidante of Hitler himself and his disillusionment with the regime appears to be largely personal. Juliana and Frank are unmarried but living together rather than divorced and separated. Frank has a sister, nephew and niece, although they are killed early in the series, and this propels him into a more active role in relation to the resistance. Juliana also has a sister whose murder by the Kempeitai early in the season instigates her search for the mysterious Man in the High Castle, as well as her having a mother and stepfather who are significant supporting characters. Joe Cinnadella is renamed Joe Blake and as he becomes closer to Juliana appears to have growing doubts about his role as a Nazi agent. Robert Childan is however a more minor character (at least in Season 1) than the original, while Ed McCarthy has a rather more prominent and active role.
There are several major additional characters introduced by the television series and numerous narrative details and the plotline differ radically from the source novel. For example, the planned Nazi pre-emptive nuclear strike on Japan, "Operation Dandelion," is apparently being prevented only by Hitler's personal refusal to authorise it, leading Heydrich and the faction demanding pre-emptive war to plot the Führer's assassination. In addition, Hawthorne Abendsen does not appear in the first season of the television version and The Grasshopper Lies Heavy is a series of newsreel films depicting multiple alternate realities rather than a novel (although this idea may actually be borrowed from Dick's later novel Valis which features a mysterious film depicting yet another dystopian alternate history of the USA). As of the Season 1 finale, these films are being tracked down by SS agents like Blake for dispatch to Hitler himself for an as-yet-unknown purpose.