Access to the expanded versions of the 16S and 23S Ribosomal RNA Mutation Databases has been improved to permit searches of the lists of alterations for all the data from (1) one specific organism, (2) one specific nucleotide position, (3) one specific phenotype, or (4) a particular author. The URL for the searchable version of the Databases is: http://ribosome.fandm.edu. The database currently consists of 1024 records, including 485 16S rRNA records from Escherichia coli, 37 16S-like rRNA records from other organisms, 421 23S rRNA records from E. coli, and 81 23S-like records from other organisms. The numbering of positions in all records corresponds to the numbering in E. coli. We welcome any suggested revisions to the database, as well as information about newly characterized 16S or 23S rRNA mutations.