Toll‐like receptors (TLRs) play a fundamental role in recognizing infectious and noxious agents as well as products of tissue damage. They are capable of initiating both protective and damaging inflammatory and immune responses. Several biotechnology and pharmaceutical companies have programmes to develop new drugs that are either: agonists of TLRs to enhance immune responses against tumours and infectious agents, or to correct allergic responses; or antagonists designed to reduce inflammation due to infection or autoimmune disease. This article reviews the commercial approaches being undertaken to develop new TLR drugs.