The fascination with gold is a story which spans millennia, however scientists have recently found a new interest for gold when it is divided into miniscule grains, such as gold nanoparticles. This scientific enthusiasm started in various fields of science in the middle of the 1980s and the present book offers a panorama of the major scientific achievements obtained with gold nanoparticles. Various topics are reviewed such as: gold nanoparticle preparation methods, their plasmon resonance and thermo-optical properties, their catalytic properties, their use in biology and medicine as well as the.