It is a dystopian work about the rise of a proto-fascist tyranny in the United States. It is perhaps the novel in which Jack London's socialist views are most explicitly on display. It is a favorite of many London aficionados. It reminds many readers of George Orwell's Nineteen Eighty-Four, and is cited by Orwell's biographer Michael Shelden as having influenced that work.
Chapter 7 of The Iron Heel is an almost verbatim copy of an ironic essay by Frank Harris; see Jack London: Accusations of plagiarism
Serious fans of science fiction also consider this novel to be a masterpiece. Fans of soft science fiction in particular see it as a forerunner of science fiction novels and stories of the 1960s and 1970s which stressed future changes in society and politics while paying much less attention to technological changes.
London's novella The Scarlet Plague, and some of his short stories, are placed in a dystopian future setting that closely resembles that of The Iron Heel, although there is no actual continuity of situations or characters.