Lincoln Prison inspection: Fears raised over safety
Inmates at Lincoln Prison have told inspectors they felt "intimidated, victimised and unsafe".
Prisons inspector Martin Lomas said although his team thought the jail was improving there was a long way to go in tackling some of the issues raised.
The prevalence of drugs were also highlighted in the report.
The National Offender Management Service said the governor and his staff had worked extremely hard and deserved credit for the progress made.
Significant overcrowding was another area for concern in the report, which followed an inspection in November.
First-night arrangements for prisoners were also described as being "chaotic".
Mr Lomas said: "Overall, Lincoln is a much improved prison. When we visited in 2012 we described a prison that was poorly led and failing.
"I think we found across the operation it was much better than it had been."
However, he said there was a perceived fear of violence among prisoners, which needed to be taken seriously and dealt with.
He added: "It is a constant battle - they have to keep on, keeping on - and while we recognise there has been much improvement - we don't shy away from making the point that more needs to be done."
Prior to the inspection, an inmate was charged with murder after a 73-year-old man was found dead in his cell, and there have been two suicides since the last inspection.
The HM Inspectorate of Prisons report also found there was no strategy in place for managing about 80 sex offenders who were described as being in denial about their crimes.
The prison was praised for promoting equality and diversity, although prisoners from black and minority ethnic backgrounds expressed more negative perceptions of the prison.
Michael Spurr, chief executive officer of the National Offender Management Service, said he was pleased the chief inspector had recognised "the significant improvements that have been made at Lincoln despite the challenging operating environment".
"The governor and his staff have worked extremely hard and deserve credit for the progress made.
"There remains more to do and we will use the recommendations in this report to support further improvements."
HMP Lincoln is a category B prison, which is also used to relieve overcrowding at other prisons in the East Midlands.