The kinins, particularly bradykinin (BK), are important mediators involved in both the initiation and progression of an inflammatory response. The pro-inflammatory effects of kinins are mediated by at least two receptors: the B2 subtype is expressed constitutively and the B1 receptor is induced following tissue inflammation and damage. The endogenous ligand for the B1 receptor is des-arg9BK, a cleavage product of the activity of carboxypeptidase on BK. Activation of B1 receptors produces a range of pro-inflammatory effects including oedema, pain and promotion of blood-borne leukocyte trafficking. In this article Amrita Ahluwalia and Mauro Perretti briefly describe the biology of BK and its receptors, and discuss the possible development of B1 receptor antagonists as novel anti-inflammatory agents.