Asthma is a chronic inflammatory disease of the lungs, characterized by increased sensitivity to bronchoconstriction associated with infiltration of immune cells and mucus hyper secretion. In South Africa, the indigenous plant Siphonochilus aethiopicus, is used by traditional health practitioners to treat colds and flu, wheezing of the chest, coughs, influenza, sinus problems and mild asthma. In this study we aimed to investigate the potential anti-inflammatory and immune-modulating properties of S. aethiopicus in vitro. The dried and powdered S. aethiopicus plant material was extracted with organic solvents. The dried extracts were screened in vitro in the transcription response, NF-B and a cytokine assay. Significant activity was observed for organic extracts of the plant in these assays. This study provides evidence that S. aethiopicus has anti-inflammatory and immune-suppressing properties in vitro. These findings may support anecdotal accounts of its effectiveness against allergic asthma.