Field horsetail (Equisetum arvense L.) is a perennial weed native to many areas of the northern hemisphere. Like other horsetail species, field horsetail is a spore-bearing plant from an ancient clade. Unlike some other horsetails, field horsetail is a problematic agricultural weed. It is especially difficult to control in low-tillage cropping systems. Neither chemical nor mechanical tactics are likely to achieve full control in a single operation. However, these tactics may be successfully combined in an integrated weed management program. This review summarizes available information about the biology, ecology, and management of field horsetail. We also note its potential value as a source of pharmaceutical compounds.