Abstract Summary: Patikaweb provides a Web interface for retrieving and analyzing biological pathways in the Patika database, which contains data integrated from various prominent public pathway databases. It features a user-friendly interface, dynamic visualization and automated layout, advanced graph-theoretic queries for extracting biologically important phenomena, local persistence capability and exporting facilities to various pathway exchange formats. Availability: The Web site is freely accessible to non-commercial users from Contact: [email protected] Supplementary information: Detailed information is available on the tool Web site (), including key features, screenshots and User’s Guide.