This study aimed to develop a mathematical model for predicting recovery potential of an obstructed kidney with poor function by a noninvasive method. We analyzed a cohort study of 93 patients who suffered from unilateral renal or ureteral stones with hydronephrosis and renography showing an ipsilateral glomerular filtration rate (GFR) <15 ml/min. We recorded clinical parameters, including age, sex, body mass index, residual renal volume (RRV), unilateral GFR, and split renal function (SRF) before percutaneous nephrostomy (PCN). After 38.16 +/- 5.87 days of drainage. Renal function was re-evaluated by renography. Almost all of the kidneys showed changes in GFR and SRF. Univariate and multivariate analysis showed that the patient's age, RRV, pre-GFR, and pre-SRF were significant factors associated with recoverability of renal function. A multiple linear regression model was developed to predict the recovery potential of the obstructed kidney.