Intergenic Sequence Inspector (ISI) is a program that helps in identifying bacterial ribonucleic acids (RNAs). It automatically extracts, selects and visualizes candidate intergenic regions (IGRs) that bear conservations between phylogenetically related species, displaying sequence and structural signatures of RNA genes encompassing putative promoters, terminators, RNA secondary structure predictions and the G+C percent of the selected sequences. ISI is intentionally modular to analyze various bacterial genomes according to their intrinsic specificities and to the available data. ISI provides a sum of information to the user who can evaluate whether or not an IGR is susceptible to express RNAs.