Around 40 members regularly attend the group at HMP Bronzefield in Surrey, which is open to staff members and prisoners who are part of resettlement programmes ahead of their release.
WI member Angeline Cross, who set up the Bronzefield group, told members' magazine WI Life: "During our meetings, the women forget that they're in prison and instead feel part of something that's really special, where learning new skills and getting to know new people offers a huge boost of confidence.
"Craft is really popular and our members loved getting involved in cutting out the lettering and hand-stitching the design for our first banner. Members are very proud of their WI being the first to be established within a prison."
In addition to honing their craft skills and learning to bake, members of the group have also hosted a coffee morning for visitors from Trumps Green WI, based in the nearby village of Virginia Water.
Opened in 2004, Bronzefield is the largest women-only prison in Europe. Run by a private company, it counts top-security category A prisoners amongst over 500 inmates.
The prison also houses some women who have been found guilty of less serious offences, or who are on remand awaiting trial.
The WI has over 200,000 members nationwide and will celebrate its centenary in 2015.
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