The Royal College of Nursing (RCN) research also uncovered concerns over the use of agency staff and the “skill mix” during shifts.
The survey’s preliminary findings were reported by RCN Scotland in a submission to Holyrood’s Health Committee on the 2018/19 draft budget.
A total of 3,300 Scottish nurses were asked about their experiences on recent shifts.
Just over one third reported the use of bank and agency staff during their most recent shift.
On average, one in eight nurses on that particular shift were supplied by an agency, the respondents said.
The submissions adds: “Respondents also reported insufficient staffing and the impact of this on patient care, with half of those responding in Scotland reporting that patient care was compromised on their last shift.
“When describing what had impacted on the ability to deliver high-quality care, one third reported not enough registered nurses and a quarter reported there were not enough healthcare support workers.
“Nearly half reported they had concerns about the skill mix (which may also include staffing beyond nursing) on their last shift/day of work.”
The RCN will publish more detailed analysis of the survey results later in the summer.
Official statistics show the use of agency nursing and midwifery staff increased in 2016/17 from the previous year.
NHS Scotland spent £166.5 million on agency staff during 2016/17, up £8.4 million on 2015/16.
Commenting on the RCN survey findings, Scottish Labour health spokesman Anas Sarwar said: “This is a deeply worrying revelation.
“It reinforces our warnings that the SNP has presided over a workforce crisis in our NHS, leaving staff over-worked, under-valued and under-resourced.
“Morale is at rock bottom in the health service, with staff reporting there simply aren’t enough of them to do the job properly. That risks compromising patient safety.
“This is part of the legacy left by Nicola Sturgeon who as health secretary slashed the number of training places for nurses and midwives.
“As a result, spending on agency nurses in Scotland has risen six-fold in just five years under the SNP, which is just one reason why our health service is in desperate need for a meaningful workforce plan.”