On 30 March 2017, EuroPris organized a one day workshop on Forecasting in Ghent, Belgium, that was hosted by the Belgian Prison Service. The Forecasting workshop is organized bi-annually. This was the third Forecasting workshop since 2012. There were 31 participants from 15 countries that joined the workshop. Presentations and discussions were on topics such as Monitoring of Forecasting outcomes; Tracking prison population forecast performance across multiple scales and data systems; Visualisation of data; Big data and the impact of the fluctuating numbers of prisoners on capacity and staff planning.