The term 'seizure,' as used in this report, means taking possession of a controlled substance and includes acquiring materials through evidence seizures and buys, as well as taking custody of found or abandoned substances. Statewide, a total of 115,864 controlled substance seizures were reported, with Federal agencies accounting for 5 percent of the total, State agencies 9.2 percent, and local law enforcement agencies 85.8 percent. Federal agencies accounted for 24.3 percent of the amount of the State total, local law enforcement agencies 47.2 percent, and State agencies 28.5 percent. Schedule I substances, as a group, represented the highest volume of grams seized, primarily because marijuana was seized more often and in greater amounts than any other controlled substance. The total reported grams of marijuana seized was 119,679,174, or 95.7 percent of the total grams of all controlled substances seized in the State. Local law enforcement agencies in eight counties reported seized substances in amounts exceeding 2 million grams. Los Angeles County accounted for 8.9 percent of the total reported grams seized by local law enforcement agencies. Federal agencies reported a combined total of 5,824 seizures amounting to 30,438,119 grams. Tabular data are provided. Appended are common weights of street quantity drugs and criteria for classifying controlled substances.