Neuropeptides are a group of signalling molecules in the nervous system that are characterised by a common basic chemical (polypeptide) structure. The importance of these substances has been established during the past 30 years. European researchers have been pioneers of neuropeptide research. The recent developments in molecular biology of neuropeptide receptors and the first clinical trials with antagonists (e.g. substance P antagonists in depression and emesis) have brought back neuropeptides as hot topic. Recent original papers in Science and New England Journal of Medicine, as well as several international reviews underline the importance of these recent developments.