Bimatoprost (Lumigan), Allergan) is a highly efficacious ocular hypotensive agent that provides good diurnal control of intraocular pressure in glaucoma and ocular hypertensive patients. Bimatoprost is a synthetic molecule that is structurally and pharmacologically similar to prostamide F(2), and appears to mimic the activity of the prostamides. Consistent with prostamide-mimetic activity, bimatoprost has potent inherent pharmacological activity in prostamide-sensitive preparations and essentially remains intact in the living primate eye. This is sufficient to explain its potent and efficacious ocular hypotensive activity, and suggests that bimatoprost is a pharmacologically unique compound.