Astronomical gamma-ray bursts, short-lived flashes of high-energy radiation, have eluded even a basic explanation for over twenty years. The 1990 Los Alamos Workshop on Gamma-Ray Bursts brought together many international scientists to summarize the current understanding of these enigmatic events, and to describe the directions of current and future research. The papers in this volume, which are based on the talks and posters presented at the Workshop, cover recent observations, searches for gamma-ray burst counterparts in other wavebands, models of the energy sources, and mechanisms for producing the continuum emissions and line features. These proceedings are an essential reference for specialists in this field, and provide a broad perspective for non-specialists and graduate students who want to keep abreast of this rapidly developing subject.