This paper reviews the current status of understanding, theory, and models for the physics of liquid fuel atomization, particularly as it applies to gas turbine and rocket applications. The paper covers five areas pertinent to atomization issues in gas turbine and rocket combustors: (1) major references in subtopic areas, (2) state-of-the-art understanding of the physical mechanisms in atomization and vaporization for gas turbine and rocket combustors, (3) models and limitations of such models, (4) references to available data sets, and (5) identification of research gaps. Although written specifically to address the requirements for rocket and gas turbine atomization, this paper identifies issues and concerns that are of interest to other users and practitioners of atomization devices, as well as developers of custom and commercial computational fluid dynamics (CFD) codes. Members of the Institute for Liquid Atomization and Spray Systems (ILASS), Americas' Rocket and Air Breathing Power Fuel Atomization Committee, made the bulk of the contributions to this paper. This paper is revised from the version presented by Benjamin and Jensen at the Eighth International Conference on Liquid Atomization and Spray Systems (ICLASS-2000), Pasadena, California, July 16-20, 2000.