The National Forensic Laboratory Information System (NFLIS) is a Drug Enforcement Administration (DEA) sponsored program that systematically collects results from drug analyses conducted by State and local forensic laboratories. The laboratories analyze substances secured in law enforcement operations across the country and offer a resource for monitoring and understanding illegal drug abuse and trafficking. In addition, the NFLIS data are used to support drug scheduling efforts and inform drug policy and drug enforcement initiatives. This midyear 2003 report on the NFLIS presents results of substances analyzed by State and local laboratories. The report is divided into three sections: national and regional estimates, major drug categories, and drug combinations. Result highlights are presented for sections one and two: (1) an estimated 874,251 drug items were analyzed by State and local laboratories in the United States from January 2003 through June 2003 with Cannabis/THC the most frequently identified drug; (2) the estimated number of drug items analyzed by State and local laboratories declined from the first quarter of 2001 through the second quarter of 2003 from 455,439 to 440,300; (3) Oxycodone and hydrocodone each experienced significant increases from the first quarter of 2001 to the second quarter of 2003; (4) overall, 34 percent of narcotic analgesic were identified as hydrocodone, 31 percent as oxycodone, and 10 percent as methadone; (5) among benzodiazepines, 54 percent were reported as alprazolam, 23 percent as diazepam, and 16 percent as clonazepam; and (6) 1 percent of all reported items contained two or more substances, most commonly heroin/cocaine. Tables, references and appendices A-C