In Northamerican folk medicine Echinacea purpurea L. Moench (purple coneflower) was used as a medicinal plant. Nowadays various formulations containing stabilized or dried pressed juice from Echinacea purpurea as an active ingredient are often administered to treat common colds. These preparations are very well tolerated and safe. Allergic reactions, mainly reversible skin reactions, may occur especially in persons showing hypersensibility after contact with plants from the Compositae family. Pharmacological data let assume purple coneflower pressed juice preparations stimulate the innate immune system and increase the resistance to common colds. In this context the stimulation of the oxidative burst as well as the modulation on monokine secretion by the pressed juice of purple coneflower are reviewed. Also relevant clinical studies are presented concerning the treatment of infections respectively of common cold.