It happened in Manchester, May 12-14, 2004. - For the fifth time since the early 1990's the Royal Society of Chemistry and the Society of the Chemical Industry jointly held their 'flavours & fragrances' conference, this time in the Manchester Conference Centre of the UMIST Manchester. The meeting saw over one hundred participants from one dozen countries, and was the largest of the series so far. In two and a half days divided into five sessions, twenty-five speakers from academia and industry alike presented their recent research results related to this exciting field, including Natural Products, Foods and Flavors, Perfumery and Olfaction, and last but not least Fragrance Chemistry. Research is more than ever central to the F&F industry with its constant demand for innovation and its frequently changing trends. Especially, in the classic and well-explored domains of musks and amber odorants fascinating new discoveries were made only very recently, which proves the endless possibilities in the search for new aroma chemicals. This was also reflected in the logo of the conference, which featured Ambrocenide? as a new powerful ambery odorant that emerged from classical cedrene chemistry - and it is as well reflected in four of the sixteen conference papers that are collected in this special issue of Chemistry & Biodiversity. With its focus on biorelevant chemicals, Chemistry & Biodiversity was predestined to publish the diverse highlight papers of the 'flavours & fragrances' conference. Fragrance and fragrance materials by definition elicit a biological response, serve as versatile signals, trigger the sense of smell and taste in various ways - and every odorant design is nothing more than 'chemistry probing nature'. But Fragrance Chemistry can also document and even preserve the biodiversity of scents, as was the topic of the lecture of Roman Kaiser, which had been published in advance as the first full paper of Chemistry & Biodiversity.