Objective: to determine whether there is an association between knowledge of the nursing
professionals about blood transfusion and the variables related to the
professional aspects. Method: this is an observational, cross-sectional and quantitative study, carried out at
a large general teaching hospital. The sample consisted of 209 nursing
professionals, obtained by simple random sampling. For data collection, a
checklist was used. In the univariate analysis, descriptive statistics and central
trend and dispersion measures were used. In the bivariate analysis, Student's
t-Test, analysis of variance and Pearson's correlation were used. To determine the
predictors, multiple linear regression was applied. The Institutional Review Board
(Opinion number 2434) approved the study. Results: the overall average knowledge score was 52.66%; in the Pre-transfusion Step, it
corresponded to 53.38%; in the Transfusion Step 51.25% and, in the
Post-transfusion Step, 62.68%. The factors related to knowledge were professional
category and received training and/or guidance to accomplish the transfusion
process (p<0.01). Conclusion: this study showed the influence of training and guidance on the knowledge and
provided a diagnosis to identify the professionals' difficulties regarding the
transfusion process.