Legislation generally provides high maximum fines for environmental offences and sentences of imprisonment for individuals. Yet the sentences set by the courts in practice are often well short of the maximum penalty. Sentencing of "serial" environmental offenders poses a particular challenge to the application of sentencing principles. Drawing on recent judicial decisions in New Zealand and Australia, this article analyses whether the sentencing of serial environmental offenders achieves the purposes of sentencing. Measures to ameliorate the challenges of sentencing serial environmental offenders are considered.