To determine the correlation of "random single voided urine protein: creatinine ratio" to "twenty four hour urine protein" at different levels of glomerular filtration rate (GFR) in Pakistani population. A total of 107 patients were included in this cross section study. Patients were divided into five groups according to the GFR. Spot urine protein: creatinine ratio and 24 hour urine protein was measured by the standard methods. The correlation coefficient ( r) between the two was calculated in each group separately. The GFR in groups 1 to 5 was > or =90, 60-89, 30-59, 15-29, and <15 ml/minute/1.73 m2 respectively. In group one correlation coefficient "r" was 0.96, in group two "r" was 0.81, in group three "r" was 0.94, in group four "r" was 0.82 and in group five "r" was 0.80. "Random single voided urine protein: creatinine ratio" may be used as an alternative to "24 hour urine collection for protein" at all levels of GFR in Pakistani population.