The roots/rhizomes of black cohosh (Actaea racemosa L. syn. Cimicifuga racemosa [L]. Nutt., Ranunculaceae) have been used traditionally by Native Americans to treat colds, rheumatism, and a variety of conditions related to women's health. In recent years black cohosh preparations have become popular dietary supplements among women seeking alternative treatments for menopausal complaints. The popularity of the plant has led to extensive phytochemical and biological investigations, including several clinical trials. Most of the phytochemical and biological research has focused on two abundant classes of compounds: the triterpene glycosides and phenolic acids. A third group of phytoconstituents that has received far less attention consists of the alkaloids and related compounds that contain nitrogen. This chapter summarizes the current state of knowledge of the chemistry and biological activities associated with this group of constituents and provides some perspective on their significance for future research on this interesting plant.