As in the United States and many other Western nations, incarceration rates in Australia and New Zealand have risen significantly over the past two decades. An interesting aspect of this trend is that internationally, female incarceration rates have increased faster than men. A number of researchers in the United States and the United Kingdom have attempted to explain this phenomenon. The current paper looks at two countries which are culturally similar and geographically close: Australia and New Zealand. Disproportionate rises in female prison populations are visible in these jurisdictions. Focussing on the 2001-2012 period, the reasons for the disproportionate rises in female incarceration rates are hypothesised and compared. It is suggested that while the drivers of the changes are in some cases similar, there are also some interesting differences between the two countries.