Mazdaznan is a neo-Zoroastrian new religious movement which held that the Earth should be restored to a garden where humanity can cooperate and converse with God. Founded at the end of the 19th century by Otoman Zar-Adusht Ha'nish, born Otto Haenisch, the religion was a revival of 6th century Mazdakism. Adherents maintained a vegetarian diet and practiced breathing exercises. Concerned with the nature of thought, emotion and behavior, Mazdaznan taught that the practical aspects of personal health could be achieved through conscious breathing, "Gah-Llama". The word Mazdaznan is said to derive from the Persian "Mazda" and "Znan", and is supposed to mean "master thought".

In 1902 the Rev. Dr. Zar-Adusht-Hanish promoted his philosophy and lessons in a monthly journal called "Sun-Worshiper" supported by health related advertisers in the Chicago area. In the February 1902 edition this "Mazdaznan Philosophy, and its Practicability to Every day Life" is listed.

Mazdaznan has been described as a "strange mixture of occult teachings, Zoroastrianism, Christianity and Lebensreform". Although the movement originally consisted of public lectures and group exercise, popular demand made a book called The Power of Breath (1958) available. Mazdaznan advocated a vegetarian diet with breathing, bowel and glandular exercises for physical, spiritual and mental development.

Its lack of lasting popularity can be attributed to the fact that besides emphasizing the importance of the individual decision, it proclaims personal responsibility for one's own fortune. Its success as a word of mouth movement that spawned similar groups can be attributed to its "tried and true" traditions of how different physical postures and ways of breathing produce predictable and controllable mental states.

Its relationship to Judeo-Christian and other religions can be deduced from its emphasis upon three historical characters: Ainyahita, Zarathustra and Jehoshua. Ainyahita, daughter of the divinely created couple (may be related to Anahita), lived 9000 years ago and is supposed to be the origin of the Aryan race, which includes the Jews and therefore Jesus of Nazareth. The traditional God character of most religions has its Mazdaznan component in "Gah-Llama" which is referred to as "intelligence," and "In the air you breathe."

The Power of Breath discusses Gah-Llama in 10 rhythmic conscious breathing exercises with illustrations, where the main goal is self-control and mastery of your body. It is in all respects, like yoga, a non-theistic tradition, in that all words for the unknown are recognized as linguistic and semantic peculiarities, with no rules except for suggestions for health, which are accompanied with a note that you know what's best for yourself.

The first centres were established in the United States in the late 19th century. Since 1917, Hanisch settled mainly in Los Angeles. By 1937 there were 52 Mazdaznan centres.

In Europe, Mazdaznan was spread by the former Californian farmers David and Frieda Ammann beginning in about 1907. David Ammann was expelled from Leipzig, Germany in 1914 due to the publication of the book Inner Studies. The main centre for Mazdaznan in Europe was the Lebensschule at Herrliberg near Zürich. One of the most famous European followers of the movement was the abstract painter Johannes Itten, who taught at the Bauhaus, who insisted on shaven heads, crimson robes and colonic irrigation.