Objectives: This study was undertaken to compare the urine protein to creatinine ratio with 24-hour urine protein estimation in pregnancy complicated by hypertension and to establish the cut-off value of the urine protein to creatinine ratio for predicting significant 24-hour proteinuria. Design: This is a comparative study and consists of a single group of 240 subjects. Setting: This study was conducted in the Department of Obstetrics and Gynecology in collaboration with the Department of Biochemistry, JIPMER, Pondicherry, India, from February 2011 to January 2013. Population: The subjects included 240 pregnant women admitted after 20 weeks of gestation to the JIPMER hospital with hypertension (≥140/90 mmHg). Patients with known cases of renal diseases, diabetes and urinary tract infection were excluded. Methods: A first voided morning sample was obtained for urine protein and creatinine estimation and urine culture. Subsequent urine samples were collected for the 24-hour urine protein estimation. Main outcome measures: The spot urine protein to creatinine ratio and 24-hour urine protein were significantly correlated (r=0.98; P<0.0001). The cut-off value for the protein to creatinine ratio as an indicator of protein excretion ≥300 mg/day was 0.285. The sensitivity and specificity were 100% and 99.02%, respectively. The positive and negative predictive values were 100% and 99%, respectively. Results: The cut-off value for the protein to creatinine ratio as an indicator of protein excretion ≥300 mg/day was 0.285 with significant correlation. Conclusion: The spot urine protein to creatinine ratio is valuable for clinical purposes.