HMP Wealstun: Prison had 200 ambulance visits in 6 months over drugs
Ambulances were called out more than 200 times in six months to drug-related incidents at a prison, according to a report.
Inspectors said HMP Wealstun in West Yorkshire was failing to tackle the "serious problem".
The category C training and resettlement prison near Wetherby holds 820 men.
The Prison and Probation Service said it was "working hard to address the issue of drugs".
Peter Clarke, the chief inspector of prisons, said the prison's performance was good, but added: "The ready availability of illicit drugs undermined much of what the prison was trying to achieve."
He said 69% of prisoners told inspectors it was easy to obtain drugs, and nearly a quarter of all prisoners said they had acquired a drug habit since entering the jail.
Mr Clarke branded this a "remarkable figure given the short time that many prisoners stayed there".
'Recover from decline'
He said: "I have deliberately focused on a number of key weaknesses, because they inevitably undermined much of the very good work that was being carried out at Wealstun.
"I have little doubt that if the key areas of illicit drug supply and failure to assess risks were to be addressed, Wealstun could recover from the decline in grades since the last inspection, and indeed move on to better serve the needs of its prisoners."
He praised improvements in living conditions and healthcare, but the report also warned that levels of self-harm had increased six-fold since the last inspection.
Phil Copple, director general for prisons at the Prison and Probation Service, said: "The Governor and her team are working hard to address the issue of drugs at HMP Wealstun.
"The new X-ray scanner is bolstering security, and the prison is working closely with the police to catch those responsible."