A 23-year-old male prison officer was taken to hospital after having his throat cut by a prisoner at HMP Nottingham.
The incident happened at the prison on Sunday morning. Officers were called to the prison at 11.15am.
The male officer has since been released from hospital.
A 25-year-old man has been arrested on suspicion of inflicting grievous bodily harm and remains in police custody.
HMP Nottingham is a category B male prison which expanded in 2010 to hold 1,060 prisoners.
An inspection report published last year found levels of violence at the prison were "very high", with 103 assaults on staff in the previous six months.
Over the same period, there had been 198 incidents where prisoners had climbed onto safety netting between landings.
"This level of disorder contributed to a tense atmosphere at the prison," HM Inspectorate of Prisons said, adding that many violent incidents, including serious ones, were not investigated at all.
The prison needed to do "much more" to tackle the problem of drugs which was "inextricably linked" to violence, chief inspector of prisons Peter Clarke Clarke said in his report.