Chaos game representation (CGR) was proposed recently to visualize nucleotide sequences as one of the first applications of this technique in the field of biochemistry.1 In this paper we would like to demonstrate that representations similar to CGR can be generalized and applied for visualizing and analyzing protein databases. Examples of applications will be presented for investigating regularities, and motifs in the primary structure of proteins, and for analyzing possible structural attachments on the super-secondary structure level of proteins. A further application will be presented for testing structure prediction methods using CGR.