Bunbury Regional Prison is a male, mixed classification prison. It has recently undergone a significant expansion with a new 160-bed unit being built inside the main prison. The main prison houses predominantly medium-security prisoners, with capacity in Unit 1 for a small number of maximum-security rated offenders, and only for a short time. Units 2, 3 and 6 accommodate medium-security prisoners. There are two minimum-security units located outside the main prison fence. Unit 4, originally known as the Pre-release Unit, accommodates up to 144 minimum-security prisoners. Prisoners eligible and approved to participate in section 95 activities in the community live in Unit 5, the capacity of which is 37.