Castoreum extract (CAS NO. 8023-83-4; FEMA NO. 2261) is a natural product prepared by direct hot-alcohol extraction of castoreum, the dried and macerated castor sac scent glands (and their secretions) from the male or female beaver. It has been used extensively in perfumery and has been added to food as a flavor ingredient for at least 80 years. Both the Flavor and Extract Manufacturers Association (FEMA) and the Food and Drug Administration (FDA) regard castoreum extract as generally recognized as safe (GRAS). Acute toxicity studies in animals indicate that castoreum extract is nontoxic by both oral and dermal routes of administration and is not irritating or phototoxic to skin. Skin sensitization has not been observed in human subject tests. Castoreum extract possesses weak antibacterial activity. A long historical use of castoreum extract as a flavoring and fragrance ingredient has resulted in no reports of human adverse reactions. On the basis of this information, low-level, long-term exposure to castoreum extract does not pose a health risk. The objective of this review is to evaluate the safety-in-use of castoreum extract as a food ingredient.