As a Voodoo priestess, Gro Mambo has blazed a trail that has helped her garner a national and international reputation. She founded Le Peristyle Haitian Sanctuary in Philadelphia, Pennsylvania, in 1982, and later incorporated Le Peristyle as a 501(c)(3) church, making her church the first church of Voodoo, or Humofor, to achieve 501(c)(3) status. She also directs her Humofor in Mariani, Haiti, Le Peristyle Sanctuary, which belonged to her late godfather Papa Hilaire Michel. She also erected the first Voodoo Sanctuary in Sao Paulo, Brazil, where government officials hung marquees over the shrines declaring them the first shrines in the country since slavery.

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Continuing her legacy, she held the first public Voodoo ceremonies in the United States. She hosted two ceremonies at the Afro-American Historical and Cultural Museum, and in Congo Square in New Orleans, Louisiana, where she held the first Haitian Voodoo ceremony since the times of Marie Laveau. In recognition of her work, the City of New Orleans proclaimed Gro Mambo an honorary citizen and the dates of those ceremonies as holidays. To this day, June 6, 1998 stands as New Orleans Festival Day.

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She is the founder of the National African Religion Congress / NARC World International, the certifying board of priests and priestesses of all African-based religion worldwide. As NARC World's founder, Gro Mambo Angélá Noványón Idizol is the first to introduce the certification system of Priests, Priestesses, Babalawos and workers of African-based religions. She has also been called as an expert witness for judicial systems to clarify information that the courts otherwise would not understand about traditional practices.