The extremely radioresistant eubacterium Deinococcus radiodurans and the phenotypically related prokaryotes, whose genomes have been completely sequenced, are presently used as model species in several laboratories to study the lethal effects of DN"-damaging and protein-oxidizing agents, particularly the effects of ionizing radiation IR . Unfortunately, providing relevant information about radioresistant prokaryotes RP in a neatly centralized and organized manner still remains a need. In this study, we designed RadioP Web resource www.radiop.org.tn to gather information about RP defined by the published literature with specific emphasis on i predicted genes that produce and protect against oxidative stress, ii predicted proteins involved in DN" repair mechanisms and iii potential uses of RP in biotechnology. RadioP allows the complete RP proteogenomes to be queried using various patterns in a user-friendly and interactive manner. The output data can be saved in plain text, Excel or HyperText Markup Language HTML formats for subsequent analyses. Moreover, RadioP provides for users a tool ST"RT "N"LY-SIS , including the previously described R-packages drc and lethal , to generate exponential or sigmoid survival curves with D and D values. Furthermore, when accessible, links to external databases are provided. Supplementary data will be included in the future when the sequences of other RP genomes will become available.