The project that grew into the compilation of The Hitler Book began shortly after the end of World War II in Europe. Joseph Stalin had doubted the official story that Adolf Hitler had indeed committed suicide, and personally believed that Hitler had fled and that the Western Allies had granted him political asylum.[1]: xxiv 

At the end of 1945, Stalin ordered the NKVD (the People's Commissariat of Internal Affairs—a precursor to the KGB) to investigate the circumstances of Hitler's supposed death and to reconstruct the last days of April 1945 inside the Führerbunker. The NKVD codenamed this project "Operation Myth." People's Commissar Sergei Kruglov was in charge of this investigation, while the actual writing of the final report was done by the security service officers Fyodor Parparov and Igor Saleyev.

In the immediate aftermath of the suicide of Adolf Hitler on 30 April 1945 and the end of World War II in Europe, the forces of the Soviet Union had immediate access to the German Reich Chancellery and the Führerbunker in Berlin. Their investigation went on for almost four years and by the time it was completed, its scope had widened from simply researching the circumstances of Hitler's death into a detailed report on Hitler's life from 1933 to 1945. The NKVD researchers had access to large numbers of documents confiscated from Hitler's headquarters and living quarters, and also were able to question many Nazis who had known Hitler personally. These included Heinz Linge, Hitler's personal assistant and valet, and Otto Günsche, Hitler's Schutzstaffel adjutant. Both men were imprisoned in Soviet gulags during the writing of the report and were subjected to "extensive, often grueling interrogation."[1]: x  To "interview" Heinz Linge for the book, for instance, the NKVD held Linge in a solitary cell, crawling with bugs, and subjected him to repeated whippings and other humiliating tortures.[1]: xxvi 

The final report, amounting to 413 typed pages, was presented to Stalin on 29 December 1949.