An Image Library of Biological Macromolecules is described, which contains image and text files related to structures of biological macromolecules. Currently, the Library has ∼3000 image files of ∼300 structures of biological macromolecules whose coordinates are available in the Protein Data Bank and in the Nucleic Acid Database. The entries include all RNA structures, ∼70 DNA structures, 150 proteins and a few carbohydrates. The Library contains further images of amino acids, of standard and modified nucleotides and of nucleic acid model structures. Each entry consists of an annotation file with bibliographic and sequence information and possibly comments, of a color-coded distance plot and of structure images. Almost all of the images are available both in a mono and in a stereo representation. Standard procedures for generating these images were strictly avoided. Therefore, mixed rendering, coloring and labeling techniques were used extensively. Since May 1995 the Library has a growing division of images in the new Virtual Reality Modeling Language (VRML) format. The Image Library of Biological Macromolecules can be accessed via the World-Wide Web (http://www.imb-jena.de/IMAGE.html). There is a large number of structures determined by experimental and/or modeling techniques which are not intended to be included into the Protein Data Bank or Nucleic Acid Database for some reason. The Image Library could be a repository of these structures and of images of these and other structures of biological macromolecules including structures which are not known at atomic detail. Authors who are willing to make available images or coordinates to the scientific community via the Image Library of Biological Macromolecules are requested to contact the author.