In pediatric and neonatal intensive care units, severity assessment of extravasation is difficult, considering the specificity of this population. The purpose of this study was to demonstrate the ability to improve the measurement of extravasation by nurses with the establishment of a standardized instrument and suitable for children. 66 nurses, randomly assigned to two groups, assessed the severity of extravasations using 15 clinical vignettes.The intervention group with the Pediatric Peripheral Intravenous Infiltration Scale (PIV Scale) (n=33) and the control group based on clinical judgment only (n=33). The reference were obtained from a group of experts. For both groups, concordance and sensitivity were calculated. Concordance and sensitivity were improved by the use of the PIV scale κ=0,62 (IC 95% ; 0,57-0,67) vs κ=0,51 (IC 95 % ; 0,45-0,57), and (69 %) vs (60 %) (p<0,001), respectively. Severity assessment of extravasation on peripheral venous accesses by nurses was improved with the use of the PIV scale, compared to clinical judgment. As this study was based on clinical vignettes, further studies are needed to confirm these results in clinical setting.