Filé powder, also called gumbo filé, is a spicy herb made from the dried and ground leaves of the sassafras tree (Sassafras albidum), native to eastern North America. Choctaw Indians of the American South (Florida, Mississippi, Alabama, Louisiana) were the first to use dried, ground sassafras leaves as a seasoning, what is now called filé, or gumbo filé, used in Creole cooking. It is used in the making of some types of gumbo, a Creole and Cajun soup/stew often served over rice; other versions of gumbo use okra or a roux as a thickener instead. Sprinkled sparingly over gumbo as a seasoning and a thickening agent, it adds a distinctive, earthy flavor and texture. Filé can provide thickening when okra is not in season. Filé translates to "string".  "Filé gumbo" is famously mentioned in the classic country song by Hank Williams Sr., Jambalaya (On The Bayou), as it is considered a staple of Cajun cuisine.
Unlike sassafras roots and bark, the tree's leaves, from which filé is produced, do not contain a detectable amount of safrole. This is significant because safrole is regarded by the U.S. government to be a weak carcinogen. The relationship between safrole and sassafras may be the origin of the widely reported belief that filé powder has a questionable effect on human health.
- Zatarain's. "Gumbo". Zatarain's. Retrieved 22 July 2011.
- Irma S. Rombauer, Marion Rombauer Becker, and Ethan Becker, Joy of Cooking, Scribner/Simon & Schuster, New York, 1997; p. 45.
- Howard Mitcham (1978), Creole Gumbo and All That Jazz, ISBN 978-0882898704, as quoted in How to make Homemade File Powder at Nola Cuisine
- Carlson, M; Thompson, Rd (Sep 1997). "Liquid chromatographic determination of safrole in sassafras-derived herbal products" (Free full text). Journal of AOAC International 80 (5): 1023–8. ISSN 1060-3271. PMID 9325580.