OBJECTIVES: This study aims to assess the knowledge, attitude and practice (KAP) of voluntary blood donation (BD) among the non-physician health-care workers of our institution, to investigate the relationship between these parameters and to determine the predictors of BD practice.BACKGROUND: KAP surveys provide a popular context-specific evidence base for the development of blood transfusion services' strategies and interventions to promote voluntary, non-remunerated BD. However, there are just few studies worldwide assessing KAP of BD among health-care workers.METHODS: This is a cross-sectional exploratory study, which took place at the 'Ippokrateio' General Hospital of Thessaloniki, Greece, a tertiary health-care institution. A specially designed, pre-tested questionnaire was distributed to all non-physician health-care workers of the hospital. A total of 1140 questionnaires were distributed. Participation in the study was optional and anonymous. Regarding data analysis, a binary logistic regression analysis was performed to describe the relationship between different elements of KAP of BD and to determine possible predictors of BD practice.RESULTS: The response rate was 25·5% (291 respondents). Logistic regression analysis revealed a positive attitude towards family replacement as an important predictor of both regular and voluntary BD, with male gender also a predictor of the latter. An inconsistency between knowledge, attitude and practice of BD was revealed.CONCLUSIONS: The present study adds valuable data on KAP of BD among health-care workers. This will help blood transfusion services to improve management practices among this group as they have the potential to provide a reliable, stable and safe source of blood products.