3-Methylindole, also known as skatole, is an organic compound with the molecular formula C9H9N. It is a white to yellowish crystalline solid with a characteristic, intense fecal odor at high concentrations, but it exhibits a pleasant floral scent when highly diluted. Structurally, it is a derivative of indole, featuring a methyl group at the 3-position of the indole ring. Its primary industrial application is in the fragrance and flavor industry. In trace amounts, it is used as a fixative and fragrance component in perfumes, contributing to floral and animalic notes. It is also employed in the synthesis of other aroma chemicals. Beyond its use in fragrances, 3-methylindole is a known intermediate in organic synthesis, particularly for the construction of more complex indole-based heterocyclic compounds used in pharmaceuticals and agrochemicals research. It is important to handle this compound with care as it is considered toxic and can cause irritation. It occurs naturally in mammalian feces, coal tar, and certain essential oils, and is also a byproduct of the microbial degradation of tryptophan in the intestines.