Over half of working nurses think their wards are "dangerously unsafe" because of low staffing levels all or some of the time, according to a snapshot survey.
The poll carried out for the Nursing Times magazine found 57% of the 526 nurses questioned believed their ward was dangerous for patients because there were too few staff.
A further 39% of nurses said staffing levels had worsened where they work over the last 12 months.
The findings come a year of the Francis Report into the failings at Stafford Hospital was published, after hundreds of people died needlessly due to neglect.
One nurse told the magazine: "Although my organisation has been recruiting more nursing staff they have been inexperienced and have had to be supervised, so in some cases have made matters harder."