A preliminary review of substance abuse treatment admission data from 2001-2005 was conducted to explore the use of methamphetamine among American Indians in treatment programs funded by Los Angeles County. Comparisons were made between primary methamphetamine users and users whose primary drug was a substance other than methamphetamine. In that period, the number of American Indians reporting methamphetamine as their primary drug in Los Angeles County significantly increased, particularly among females. (Contains 2 tables, 3 figures and 2 footnotes.)