Program findings for 1996 and the first half of 1997 indicated drug use in the arrestee population declined during the latter part of 1996 but rose in the first half of 1997. Juvenile drug use increased to 64 percent in the first quarter of 1997. Marijuana continued to be the most frequently used by young people, with 50 percent testing positive during the first half of 1997. About 12 percent of young people were arrested for drug and alcohol offenses, 35 percent were arrested for violent crimes, and 27 percent were arrested for property crimes. Juvenile self- reported drug use in 1996 indicated 80 percent had used tobacco, 93 percent had used alcohol, 13 percent had smoked crack, 40 percent had used methamphetamines, 14 percent had used phencyclidine (PCP), and 7 percent had used heroin. Overall, cocaine and heroin use continued to decline among all populations, while methamphetamine use appeared to be rising. About half of methamphetamine users were white and over 31 years of age. Adult and juvenile methamphetamine users differed with respect to how the drug was ingested. Most juveniles reported smoking methamphetamine, whereas almost half of adults snorted the drug. Additional data on drug use in the San Diego region is provided in three appendixes. Tables and figures