It is most remembered for US marketing slogans devised by Hallmark Releasing Corp. that included "Positively the most horrifying film ever made" and "Rated V for Violence", while sick bags were given free to the audience upon admission.

Christian arrives in a small Alpine village, where a self-sanctioned witch hunter named Albino has taken control over the townspeople, making unwarranted accusations of witchcraft against women who refuse his sexual advances.

As Cumberland enforces tortures and executions based on Albino's indictments, Christian begins to see evidence that the trials in the village are scams to rob people of their land, money, and other personal belongings of value.

Christian observes Cumberland give Baron Daumer, a man accused of sorcery, an ultimatum: If he surrenders his inherited land, his life will be spared, but if not, he will be executed.

Christian helps Vanessa escape her prison cell, and she incites a revolt among the villagers to overthrow the witch hunters, revealing their corruption.

A series of executions begin, including that of Baron, who is beheaded, but the proceedings are stopped when the incensed villagers descend on the scene and attack the witch hunters.

Armstrong claims in his commentary track on the Blu-ray release by Arrow that they filmed nothing significant, although he did add the water torture scene featuring Hoven as an actor at the latter's request.

The film (which The Aurum Film Encyclopedia: Horror calls "grotesquely sadistic"[3]) contains very strong simulations of graphic torture including a woman's tongue being ripped out of her head by tongue pincers, nuns being raped, nails to probe for the Devil's spot, whipping posts, fingers being cut off, racks and multitudes of vicious beatings.

The opening credits and voiceover make the exaggerated claim that over eight million people were condemned as witches and killed during the period in which the film is set.

[5] Hallmark's marketing campaign for the film highlighted its violent content, describing it as "rated V for violence,"[6] and sick bags were given free to the audience upon admission.

[11][12] In 2017 the Cine-Excess eJournal devoted a special issue to the film and its sequel, Mark of the Devil Part II, which includes a range of extensive articles (about topics such as authorship, marketing and censorship) and an interview with Joyce and Percy Hoven.

[13] Producer Hoven delivered the official sequel, Mark of the Devil Part II (German: Hexen geschändet und zu Tode gequält) in 1973.

[citation needed] In addition, several VHS companies sought to exploit the title's notoriety by retitling several unrelated European horror films as sequels.