Artemisia L. is a genus of small herbs and shrubs found in northern temperate regions. It belongs to the important family Asteraceae, one of the most numerous plant groupings, which comprises about 1000 genera and over 20000 species. Artemisia has a broad spectrum of bioactivity, owing to the presence of several active ingredients or secondary metabolites, which work through various modes of action. It has widespread pharmacological activities and has been used as traditional medicine since ancient times as an anthelmintic, antispasmodic, antirheumatic, and antibacterial agent and for the treatment of malaria, hepatitis, cancer, inflammation, and menstrual-related disorders. This review comprises the updated information about the ethnomedical uses and health benefits of various Artemisia spp. and general information about bioactive compounds and free radicals.