The LIPID MAPS Structure Database (LMSD) is a comprehensive relational database that contains structures and annotations of biologically relevant lipids. The database integrates lipid structures from four sources: LIPID MAPS Consortium's core laboratories and partners, lipids identified by LIPID MAPS experiments, computationally generated structures, and manually curated lipids from public sources like LIPID BANK and LIPIDAT. All lipid structures are drawn consistently using a defined drawing scheme, and each lipid is assigned a unique 12-character LIPID MAPS identifier (LM ID). LMSD supports both classification-based and text-based search options, allowing users to retrieve lipids based on their category, class, subclass, and other data fields. Structure-based searches can perform substructure or exact matches. The database also includes links to external databases and is publicly available at www.lipidmaps.org/data/structure/. As of November 2006, LMSD contains 9,143 lipids, and future work involves integrating lipid data with the LIPID MAPS Proteome Database (LMPD) and associating lipids with metabolic pathways.The LIPID MAPS Structure Database (LMSD) is a comprehensive relational database that contains structures and annotations of biologically relevant lipids. The database integrates lipid structures from four sources: LIPID MAPS Consortium's core laboratories and partners, lipids identified by LIPID MAPS experiments, computationally generated structures, and manually curated lipids from public sources like LIPID BANK and LIPIDAT. All lipid structures are drawn consistently using a defined drawing scheme, and each lipid is assigned a unique 12-character LIPID MAPS identifier (LM ID). LMSD supports both classification-based and text-based search options, allowing users to retrieve lipids based on their category, class, subclass, and other data fields. Structure-based searches can perform substructure or exact matches. The database also includes links to external databases and is publicly available at www.lipidmaps.org/data/structure/. As of November 2006, LMSD contains 9,143 lipids, and future work involves integrating lipid data with the LIPID MAPS Proteome Database (LMPD) and associating lipids with metabolic pathways.