Overall, there were slight yet significant declines in recidivism rates since 1984 for most this population. Estimated probabilities of recidivism dropped from 48 percent to 45 percent for male non-Aborigines, from 80 percent to 76 percent for Aborigines, and from 75 percent to 69 percent for female Aborigines. The estimate of non-aboriginal female recidivism increased from 29 percent to 36 percent, but this estimate (with high confidence intervals) is relatively unreliable. A declining trend in recidivism over the 1975-1980 period leveled off from 1981-1985. These trends were related to important alterations in the definitions of the law and particularly to the decriminalization of drunkenness and the introduction of mandatory prison for repeat offenses of drunk driving. Recidivism varied significantly with other demographic and institutional factors. 10 notes, 1 figures, 5 tables, and 48 references