For almost all drink-driving offenses, the legislation doubled the maximum penalties for both the first offense and any subsequent offense. These harsher penalties included doubling the maximum jail terms for mid-range (BAC 0.08g/100ml to less than 0.15g/100ml) and high range (BAC 0.15g/100ml and higher) drink-driving offenses, as well as doubling the maximum license suspension periods and the maximum fines for all offenses. Other amendments included mandatory 3-month minimum license suspensions for special-range and low-range offenses and the doubling of minimum license suspensions for mid-range and high-range drink-driving offenses. To assess the impact of these penalty increases on recidivism, this study compared the reoffending rates of two offender cohorts: individuals convicted of a Prescribed Concentration of Alcohol (PCA) offense from January 1, 1997, through December 31, 1997, and individuals convicted of a PCA offense from January 1, 1999, through December 31, 1999. Court appearances for new drink-driving offenses were used to index recidivism. The likelihood of recidivism within 3 years of conviction was compared across offender groups by using logistic regression techniques. The findings apparently suggest that the harsher penalties decreased rates of drink-driving reoffending; however, other explanations for the reduction must be discounted before the reduction can be attributed to the legislation. 10 tables, 2 figures, 21 notes, and 13 references