Coeliac disease is an immune-mediated inflammation of the small intestine caused by sensitivity to dietary gluten and related proteins in genetically sensitive individuals. Recently, a novel gluten-related disorder has gained significant interest from the scientific community and mass media. This condition, known as non-coeliac gluten sensitivity, is characterised by gastrointestinal or extra-intestinal symptoms that respond to gluten withdrawal without evidence of underlying coeliac disease. Its symptoms overlap considerably with those of irritable bowel syndrome and the number of individuals embracing a gluten-free diet is rapidly growing. No discriminative markers to support a diagnosis of gluten sensitivity have been identified; the perceived response to a gluten-free diet after exclusion of coeliac disease is currently the best diagnostic and therapeutic marker. Its pathogenesis remains obscure but may be related to non-gliadin molecules in grains that stimulate the innate immune system of the intestine. Here, we summarise the current knowledge on this novel condition.