Valerian is a traditional herbal sleep remedy that has been studied with a variety of methodologic designs using multiple dosages and preparations. Research has focused on subjective evaluations of sleep patterns, particularly sleep latency, and study populations have primarily consisted of self-described poor sleepers. Valerian improves subjective experiences of sleep when taken nightly over one- to two-week periods, and it appears to be a safe sedative/hypnotic choice in patients with mild to moderate insomnia. The evidence for single-dose effect is contradictory. Valerian is also used in patients with mild anxiety, but the data supporting this indication are limited. Although the adverse effect profile and tolerability of this herb are excellent, long-term safety studies are lacking.