Open institutions are:

Helsinki Open Prison/Suomenlinna Unit, Kerava Prison/Kerava Open Prison Unit, Vanaja Prison, Käyrä Prison, Vilppula Prison, Satakunta Prison, Vilppula Prison, Konnunsuo Prison/Hamina Open Work Colony, Naarajärvi Prison, Sulkava Prison, Juuka Prison, Laukaa Prison, Pelso Prison/Kestilä Open Prison Unit, Ylitornio Prison

Inmates participating in work or other activities and who are considered to suit in freer circumstances and are not likely to leave the institution without permission, are placed in open institutions. In open institutions inmates always use their own clothes. All open institutions are intoxicant-free institutions, in which an inmate is required to controlled commitment not to use intoxicants.

In open institutions prisoners are paid wages for their work of which they pay taxes and their keep. Wages are also subject to execution. For studies and participation in other activities expense allowance is paid which is also taxable.

In 2008 the average prison population in open institutions was 877.