A prospective survey was conducted over six months in order to estimate the proportion of reported occupational needlestick injuries sustained by National Health Service (NHS) Scotland staff that could have been prevented through either safety device introduction, improved guideline adherence, guideline revision or a combination of these. This survey involved the administration of a standard proforma to healthcare workers followed by an expert panel assessment. All acute and primary care NHS Scotland trusts, the Scottish Ambulance Service and the Scottish National Blood Transfusion Service were included. Proforma and expert panel assessment data were available for 64% of injuries (952/1497) reported by healthcare staff. These injuries were all percutaneous. The expert panel concluded that: 56% of all injuries and 80% of venepuncture/injection administration injuries would probably/definitely have been prevented through safety device usage, 52% of all injuries and 56% of venepuncture/injection administration injuries would probably/definitely have been prevented through guideline adherence and 72% of all injuries and 88% of venepuncture/injection administration injuries would probably/definitely have been prevented through either intervention. Multi-factorial analysis indicated that injuries sustained through venepuncture/injection administration were significantly more likely to be prevented through safety device usage [adjusted odds ratio (OR) 5.09, 95% confidence intervals (CI) 3.11-8.31 and adjusted OR 2.70, 95% CI 1.64-4.45, respectively], and significantly less likely to be prevented through guideline adherence (adjusted OR 0.26, 95% CI 0.11-0.60 and adjusted OR 0.31, 95% CI 0.12-0.78, respectively). Injuries sustained after completing procedures were significantly more likely to be prevented through safety device usage and guideline adherence. The study's findings support the need for improvements to staff's adherence to needlestick injury guidelines and appropriate implementation of safety devices for venepuncture and injection administration.