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, just over one third reporting 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 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 £8.4m on 2015-16.
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.
“This is part of the legacy left by Nicola Sturgeon who as health secretary slashed the number of training places for nurses and midwives.”
Lib Dem MSP Alex Cole-Hamilton said: “This is a damning insight into the state of the NHS in Scotland that should shame the SNP.”
Health secretary Shona Robison said whole-time equivalent nursing and midwifery staff had increased by 3,300 compared with five years ago, while training places have also risen 4.7 per cent for 2017-18. Last year agency staff represented 0.4 per cent of the total NHS nursing workforce, she added.
Ms Robison said: “We’re working with health boards to reduce the overall use of agency staff.
“Our recently published NHS workforce plan also sets out a commitment to delivering around 2,600 additional nursing and midwifery training places by the end of this Parliament.”
Scottish Conservative health spokesman Miles Briggs said: “This falls completely on the SNP’s head, and it must act swiftly to address these very serious concerns.”
Last week Audit Scotland said a failure to plan for the long-term future of the NHS in Scotland has led to a staffing “crisis” as the service struggles to recuit senior medics and nurses.
The spending watchdog said one in five consultant posts are standing vacant at some health boards, while the impact of the ageing nursing workforce could leave the NHS 5,000 short in just five years’ time.