Technical Abstract: The USDA Nutrient Database for Standard Reference, Release 23 contains data for over 7,600 food items for up to 146 food components when a complete profile is available for a food item. It replaces the previous release, SR22, issued in September 2009. Data in SR23 supersede values in the printed handbooks and previous electronic releases of the database. A major application of SR includes the Food and Nutrient Database for Dietary Surveys (FNDDS) by the Food Surveys Research Group. The FNDDS is used to process dietary data records from the survey What We Eat in America, the dietary intake component of the National Health and Nutrition Examination Survey. Major changes made to the SR database since the last release include the addition of data for menaquinone-4 and dihydrophylloquinone. A section on Notes on Foods for Beef and Pork Products has been added to the documentation. The Notes give additional information about the foods such as the definitions of lean and fat and a brief description of NDL research projects conducted to generate nutrient data. Food descriptions for a number of food groups, primarily those for agricultural commodities, have been assigned factor terms using the LanguaL Thesaurus to enhance international harmonization and information retrieval. Over 200 new foods have been added to the database. Among these are: ground turkey (raw and cooked) at three fat levels; a variety of new breakfast cereals; several new oils that are being used in commercial products; sorghum and millet flour; eight frozen brand-name pizza items; and 12 new beef chuck cuts (raw and cooked) at three grade levels. As part of an ongoing effort to expand the number of food items in the database for special population groups, profiles for five Hopi foods and a number of Latino cheeses, fruits, crackers, and restaurant items have been added. A complete list of the added food items is in the ADD_FOOD file. Foods with updated nutrient values include: 19 species of fish; raw eggs; selected non-enhanced fresh pork loin cuts; and fast-food french fries to reflect new fatty acid profiles. Foods which are major contributors of sodium to the diet—primarily processed foods—have been reviewed using data from company web sites and package labels and where the difference from previously published values is greater than or equal to 10% per 100g, the sodium value has been updated. These can be found in the CHG_NUTR file. A few breakfast cereals and other brand-name products that are no longer on the market have been deleted. A complete list of deleted food items is in the DEL_FOOD file. The database is now provided in the two relational formats (ASCII and Microsoft Access). There are four principal files: Food Description, Nutrient Data, Gram Weight, and Footnotes; and six support files: Nutrient Definition, Food Group Description, Source Code, Derivation Code, Sources of Data File, and Sources of Data Link File. Update files for the database, intended for users who have obtained SR22 or earlier releases and wish to perform their own updates, are provided. An abbreviated file is provided as a flat file and as a MS Excel spreadsheet. The abbreviated file does not include values for alcohol, caffeine, phytosterols, starch, theobromine, vitamin D2, vitamin D3, individual amino acids, individual fatty acids, individual sugars, fluoride, betaine, menaquinone-4, and dihydrophylloquinone. The data are available to search or download from the Nutrient Data Laboratory Web site on the Internet http://www.ars.usda.gov/nutrientdata.