HMIP Reports, HMP Guys Marsh

The prison was given an Independent Review of Progress in November 2025, the full report can be read on the HM Inspectorate of Prisons website, just follow the links below. In their latest report the inspectors said:

HMP Guys Marsh is a category C training and resettlement prison for adult men near Shaftesbury, Dorset, run by HM Prison and Probation Service, holding 480 prisoners against a baseline certified normal capacity of 476. A full inspection in January 2025 had rated safety and respect both Poor, declines from Reasonably Good, and purposeful activity and preparation for release both Not Sufficiently Good, unchanged. This Independent Review of Progress, carried out in November 2025, checks progress against the concerns raised then rather than re-scoring the four healthy prison tests.

Inspectors found violence had fallen by around a third since the January 2025 inspection, with use of force down around 30%, and self-harm incidents had fallen from 528 to 206 over comparable six-month periods. Staff availability had risen from around 60% to 80%, supporting a more consistent regime, waiting lists for English and maths had been eliminated, and attendance at allocated activities had improved from around a third of prisoners to just over two-thirds.

Even so, inspectors found insufficient progress on four of eight concerns raised. The positive drug test rate averaged around 41%, among the highest of any category C prison, healthcare still offered only nine external hospital appointment slots a week with waits of up to six months, and leadership training for first-line managers remained inadequate. Charlie Taylor said the prison was in a much stronger position than at the time of the original inspection, crediting the governor’s leadership for the progress made.

Charlie Taylor
HM Chief Inspector of Prisons
December 2025

HMP Guys Marsh

To read the full reports, go to the HM Inspectorate of Prisons website or follow the links below: