Background: Glomerular Filtration Rate (GFR) is the amount of plasma filtered throughrnglomerular capillaries of both kidneys per minute. It is used to measure the function of kidneyrnand to know its status. GFR measurement can be done by using endogenous and exogenousrnfiltration markers. But this measurement is expensive, time consuming and inconvenient tornpatients. To alleviate these problem we can estimate GFR by using Cockcroft- Gault, MDRD andrnCKDâ€“EPI equations.GFR estimating equations are affected by sex, age, race, muscle mass,rnweight and height of an individual. However, the relation GFR estimating equations withrncreatinine clearance using these physiologic variables have not been clearly evaluated inrnEthiopia.rnHypothesis: The current study hypothesized that there will be a difference between GFRrnestimating equations (CG, MDRD and CKD-EPI) and creatinine clearance.rnObjective: The objective of study was to compare GFR estimating equations with creatininernclearance among patients who visit renal unit of Tikur Anbessa Specialized Hospital.rnMaterials and Methods: Cross sectional study was conducted to compare GFR estimatingrnequations with that of creatinine clearance among 123 patients who visit renal unit of TASHrnfrom May 20 to April 16 / 2013. A convenient sampling was used in the study to select the studyrnparticipants. Data was collected by using questionnaire, test tube, 5ml syringe with needle, urinerncollecting bag, balance and meter. Five ml of venous blood and 24 hour urine were taken fromrneach participant to determine serum and urine creatinine concentration respectively. Serumrncreatinine was determined by using fully automatedrnHITACHI 902 chemistry analyzer.rnWhereas, urine creatinine concentration was determined by using automated autolab 18rnchemistry analyzer. Descriptive statistic, Paired sample t test, Bland-Altman analysis andrncorrelation were carried out.P-value < 0.05 was considered as statistical significant and 95% CIrnused.rnResult: Of 123 study participants 52 (42.3%) were males and 71 (57.7%) were females. Theirrnmean age was 39.9 + 16.7 years. Mean GFR were 49.59+ 32.40, 56.15+33.70, 65.53+52.80 andrn80.52+80.52 ml/min with creatinine clearance, Cockroft-Gault, MDRD and CKD-EPIrnrespectively. GFR estimating equations significantly overestimate mGFRCcr by 6.56, 15.94 andrn30.93 ml/min with CG, MDRD and CKD- EPI respectively (p