AbstractAims and Objectives :To compare the spot urine Protein to Creatinine ratio with 24-hour protein estimation and to establish the cut-off value of urine Protein to Creatinine ratio in predicting significant proteinuria, in pregnancy complicated by hypertension. Materials and Methods: Comparative study consisting of single group, of 1500 admitted pregnant women after 20 weeks of gestation with hypertension of 140/90 mm of Hg. Women with pre existing renal diseases, diabetes or urinary tract infection were excluded. First voided morning urine sample was taken for urine protein and creatinine estimation and urine culture. Subsequent urine samples were collected for 24 hours protein estimation. Urine protein estimation was done by colorimetric method and creatinine estimation by modified Jaffe’s method using auto analyzer. The Receiver-Operator Characteristics (ROC) was used for comparison. With 300mg proteinuria as true positive and < 300mg proteinuria as true negative. Results: The area under the ROC curve is 0.995(95% confidence interval). With An excellent degree of correlation a cut off value of 0.285 has sensitivity 100%, specificity 99.65%, positive predictive value 99.56%, and negative predictive value 100%. Conclusion: The cut-off value of spot urine Protein to Creatinine ratio is 0.285 mg protein/ mg creatinine. The level below this is not associated with significant porteinuria and further testing is unnecessary.