The number of females arrested for Index crimes has increased between 1970 and 1980, and this increase is not only absolute, but also relative. This increase is due largely to increases in arrests for larceny-theft, which accounted for 83 percent of the increase in female Index arrests nationally, and for 93 percent of the increase in Illinois. The proportion of females arrested for violent Index offenses has remained relatively constant; males continue to compose 90 percent or more of those arrested for violent Index crimes, both nationally and in Illinois. Five figures, 12 tables, and a 25-item bibliography are included.