Pelargonium species indigenous to areas of southern Africa are widely used by traditional healers and the native population as a general remedy for the treatment of dysentery, diarrhoea, hepatic complaints, wounds, colds, and infections of the respiratory  tract including tuberculosis. Compositional studies of Pelargonium sidoides Pelargonium reniforme, forming the origin of the popular drug umckaloabo, have led to the characterization  of about 65 various metabolites including phenolic and cinnamic acids, tannins, flavonoids and coumarins with significant differences in their individual patterns of constituents . In addition, the composition of the essential oils of both species has been analysed. As regards the claimed and documented efficacy of umckaloabo, fairly high antibacterial activities against pathogens which are primarily responsible for respiratory  tract infections, and the immune modulatory potential as assessed in in vitro infection models provide for a rational basis of the therapeutic use of umckaloabo. Recent clinical studies have confirmed its efficacy in conditions such as respiratory tract infections.