Noise in physical systems - as a consequence of the corpuscular nature of matter - conveys information about microscopic mechanisms determining the macroscopic behavior of the system. Besides being a source of information, noise also represents a source of annoying disturbances which affect information transMission along a physical system. Therefore, noise analysis can promote our insight into the behavior of a physical system, as well as our knowledge of the natural constraints imposed upon physical-information transmission channels and devices. In recent years the continuous scientific and technical interest in noise problems has led to a remarkable progress in the understanding of noise phenomena. This progress is reflected by the rich material presented at the Fifth International Conference on Noise in Physical Systems. The conference papers originally published in these proceedings cover the various aspects of today's noise research in the fields of solid-state devices, l/f-noise, magnetic and superconducting materials, measuring methods, and theory of fluctuations. Each session of the conference was introduced by one or two invited review lectures which are included in these proceedings in full length. The 12 invited papers and more than 40 contributed papers on specific topics (only three of them have been omitted from the proceedings since they will be published elsewhere) provide a comprehensive survey of the current state-of-the-art and recent advances of noise analysis.