Background Medical staff members are exposed to the risk of sharps injuries, which may result in contracting blood-borne infections. The objective of this quasi-experimental pre-test/post-test research study was to examine the effectiveness of an intervention designed through a participatory process to improve knowledge and safe work practices, as well as to reduce sharps injuries among nurses.

Methods The study population was surgical nurses from 16 randomly selected hospitals in north-western Poland. Data were collected between 2009–2011 with the use of self-administered, ano-nymous pre-intervention/post-intervention questionnaires containing records of demographic cha-racteristics, self-reported sharps injuries, knowledge (12 items) and practices on injection safety, before/1 year after the educational intervention which included a 2 hour lecture.

Results Of 91 participants (mean age 42.8, range 24–59 years) for whom the pre-intervention and post-intervention questionnaires could be directly matched, 20.9% worked at teaching, 15.4% – at other urban, 63.7% – at provincial hospitals; 64.8% were employed at surgical, 24.2% – at gynaecological wards, 11.0% – in the admitting area. The mean level of knowledge on injection safety before the intervention was 3.09, it increased to 4.12 after (p < 0.001), including the improvement of the knowledge of the post-exposure prophylaxis (p < 0.001). Before the intervention 48.4% of respondents had had a needle-stick injury in the previous year, the number decreased (20.9%) after the intervention, p < 0.001; before intervention 47.5% reported recapping needles after use, and 30.0% – after, p < 0.05.

Conclusions Despite a high risk of contracting a blood-borne infection due to unsafe practices at work and numerous sharps injuries, surgical nurses had alarmingly low knowledge on injection safety. Educational intervention can have a long-term positive impact on the improvement of knowledge and safe work practices and reduce sharps injuries.