A toxicologic and dermatologic review of 2-(3,7-dimethyl-2,6-octadienyl)cyclopentanone when used as a fragrance ingredient is presented. 2-(3,7-Dimethyl-2,6-octadienyl)cyclopentanone is a member of the fragrance structural group Ketones Cyclopentanones and Cyclopentenones. The common characteristic structural element of the group members is a cyclopentanone or cyclopentenone ring with a straight or branched chain alkane or alkene substituent. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 2-(3,7-dimethyl-2,6-octadienyl)cyclopentanone were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, and skin sensitization data. A safety assessment of the entire Ketones Cyclopentanones and Cyclopentenones will be published simultaneously with this document; please refer to Belsito et al. (2012) for an overall assessment of the safe use of this material and all Ketones Cyclopentanones and Cyclopentenones in fragrances.