The PROSITE database, maintained by the Swiss Institute of Bioinformatics, is a comprehensive resource for identifying conserved protein motifs and domains. It consists of patterns and profiles, each linked to detailed documentation providing biological information. Recent developments include automated updates of patterns to minimize false positives and negatives, a new functional prediction tool called ProRule, and enhanced web functionality. ProRule generates precise functional annotations for proteins identified by PROSITE profiles. The ScanProsite web page now offers detailed functional information, including residue-level predictions and domain visualization. The database has been updated to reflect the growing size of protein databases and the need for more specific annotations. PROSITE and ProRule are freely available to academic users, with commercial licenses available through the Swiss Institute of Bioinformatics or its commercial representative, Geneva Bioinformatics.The PROSITE database, maintained by the Swiss Institute of Bioinformatics, is a comprehensive resource for identifying conserved protein motifs and domains. It consists of patterns and profiles, each linked to detailed documentation providing biological information. Recent developments include automated updates of patterns to minimize false positives and negatives, a new functional prediction tool called ProRule, and enhanced web functionality. ProRule generates precise functional annotations for proteins identified by PROSITE profiles. The ScanProsite web page now offers detailed functional information, including residue-level predictions and domain visualization. The database has been updated to reflect the growing size of protein databases and the need for more specific annotations. PROSITE and ProRule are freely available to academic users, with commercial licenses available through the Swiss Institute of Bioinformatics or its commercial representative, Geneva Bioinformatics.