The revised sentencing guideline stemmed from the New South Wales (NSW) Attorney General's application to the Court of Criminal Appeal for a guideline judgment with reference to a high range PCA drunk-driving offense. A particular concern was that too many of these offenders were receiving s 10 orders, i.e., orders that resulted in either an outright dismissal or a conditional discharge that avoids the usual consequences of a recorded conviction and sentence. On September 8, 2004, the NSW Court of Criminal Appeal delivered a guideline judgment for the offense. The study reported in this paper examined sentencing patterns for high range PCA offenses before and after the guideline was delivered. Further, it examined the results of sentence appeals to the District Court, so as to determine whether there has been any change in the nature and outcomes of such appeals since the promulgation of the guideline. This involved an analysis of trends in the penalties imposed for high range PCA offenses over a 2-year period (2003-2004). Although the use of s 10 orders for high range PCA offenses was decreasing over the 12 months prior to the new sentencing guideline, it decreased further in the postguideline period, from 5.6 percent just prior to the guideline to 2.2 percent in the postguideline period. There was a corresponding increase in the percentage of such offenders who had their drivers licenses suspended. There was also a more exaggerated distinction in the severity of sentences between first offenders and repeat offenders, particularly when repeat offenses continued to involve high range PCA. The revised guideline is apparently being implemented by the courts. 12 figures and 3 tables