Some of the current uses of computers in aiding the interpretation of electron micrographs, mainly of biological materials, are reviewed. Most of the literature covered relates to procedures designed to improve the extraction of useful information from micrographs. These range from simple digital filtration techniques for removing noise, through averaging techniques to three-dimensional reconstructions. Emphasis is placed on descriptions of applications rather than discussions of theoretical aspects. An alternative approach to interpretation is also discussed, namely that of computer generation of models of biological structures. Previous publications are reviewed, but there is also a more extended description of a system for generating models of helical particles and of two dimensional periodic structures which has been developed in the author's laboratory.