In an effort to improve size structure of Murray cod, Maccullochella peelii, size limits changed from a 600 mm minimum length limit, to a 550-750 mm harvest slot in 2014 across three states (NSW, Australian Capital Territory and Victoria). In order to better understand the initial effects of the regulatory change we examined Murray cod population characteristics in a section of the Murrumbidgee River over a 8 year period (4 year pre slot limit and 4 years post slot limit). We found some indication of truncation in length at the minimum sizes under both a minimum size limit and also under a harvest slot. It is therefore vital to continue monitoring Murray cod populations as they adjust to changing harvest restrictions, fishing effort, and environmental conditions. In this regard, the collection of time-series data should be regarded as essential for fisheries managers to understand changes within a fishery and the effectiveness of interventions.