This chapter reviews the agricultural role of the Brassicaceae (Cruciferae) or mustard family. The family includes many economically important edible and industrial oilseed, vegetable, condiment, and fodder crop, such as. It also includes the molecular plant model, such as Arabidopsis thaliana. Current crops are reviewed and new and underutilized crucifer crop species discussed. Proposed new uses for these crops, such as biofuel platforms or green manure covers or biofumigants, are also briefly reviewed. The family also contains a rich source of agronomic and economic traits in its highly diverse wild germplasm. Traits discussed in this chapter include morphological and chemical traits; physiological traits such as C3–C4 photosynthesis, cytoplasmic male sterility, apomixis, and regeneration or transformation ability; and tolerances to various stresses such as salt, heavy metals, cold, drought, herbicides, diseases, insect, and nematode pests. These traits are of potential value in crop improvement programs and many wild crucifers now serve as model species in their study.