The Advanced Study Institute on Molecular Electro-Optics was held on the campus of the Rensselaer Polytechnic Institute, Troy, New York, USA, from July 14 through July 24, 1980. This Advanced Study Institute was attended by sixteen invited lecturers and by forty-eight other participants. The present volume contains the texts of all of the invited lectures presented at the Institute. Although these lectures were supplemented by many animated discussions and by numerous short contributed papers, it was not possible to include these in the present volume. Molecular electro-optics is a difficult subject for research because it incorporates areas of theoretical physics such as elec­ tromagnetic theory and hydrodynamics of rotational diffusion, ex­ perimental physics such as lasers, optics, electric pulsers, and data collection via analog to digital converters and signal aver­ agers, and physical chemistry of macromolecules and colloids in solution (colloid science, biophysical chemistry, double layer polarization). This volume includes chapters on all of these subjects as well as introductions to magnets-optics and to elec­ trophoretic light scattering. The Advanced Study Institute was sponsored mainly by the North Atlantic Treaty Organization whose financial support made this meeting possible. Additional financial aid was supplied by the National Institutes of Health of the USA through their Fogarty International Center and the National Institute for Arthritis, Metabolism, and Digestive Diseases. Industrial contri­ buters consisted of the General Electric Company, Cober Electronics, and Malvern Scientific Corporation.