Introduction: Central Venous Pressure (CVP) measurement is the recommended method for assessment of intravascular status in paediatric shock. The role of Ultrasonography guided measurement of respiratory collapsibility in inferior vena cava diameter (IVC-CI) as a newer, non-invasive adjunct to CVP measurement has been evaluated. This study was done to determine the effectiveness of CVP and IVC-CI in predicting fluid responsiveness in cases of paediatric shock. Material and Methods:This prospective observational study was done in 107 fluid refractory shock patients aged 1-14 years. An informed consent was obtained. Baseline vitals, CVP and IVC-CI were measured before and after a crystalloid Fluid Bolus of 20ml per Kg BW. The changes in CVP and IVC-CI were noted and were correlated to the clinical response. A rise of ≥15% in Cardiac Output was taken as positive fluid response.Results: Mean age of the patients was 7.6years (±4.153). The mean CVP in fluid responders and non-responders was 6.58 (±2.64) and 11.22 (±6.12), while the mean IVC-CI was 46.57% (±23.34) and 25.62% (±23.28) respectively. There was significant inverse correlation between CVP and IVC-CI (P<0.01) in both fluid responders and non-responders. At CVP ≤8.25, sensitivity was 80% and specificity was 99% for predicting fluid responsiveness. When IVC-CI was ≥ 33.5%, sensitivity was 87% and specificity was 86%. Thus IVC-CI has better sensitivity put poor specificity to predict fluid responsiveness than CVP. Conclusion:Both CVP and IVC-CI are good predictors of volume responsiveness. A shift from hypovolemic to euvolemic status was associated with gradual fall in mean IVC-CI values with progressive rise of CVP values. IVC-CI can provide a useful guide for non-invasive intravascular volume status assessment in critically ill patients.