The fourth workshop in the series devoted to the investigation of fundamental interactions and symmetries as manifested in the physics of reactor neutrons and neutrinos was held at the Institut Laue-Langevin (ILL), Grenoble, from October 22–24, 1998 and was sponsored by the ILL and the city of Grenoble. More than 100 scientists from I I countries around the world attended the “Particle Physics with Slow Neutrons” workshop.