Nuclear medicine results before, early and late after percutaneous transluminal angioplasty (PTA) were evaluated. On the one hand this study was based on the results of the I-131-Hippuran clearance according to Oberhausen, including the time to maximum (Tmax) and half life time of renal elimination (EHWZ). On the other hand data from renal scintigraphy with Tc-99m-DTPA (perfusion and nephrographic phase) were used. Values of all split functions exhibit a progressive improvement between early and late controls. Glomerular filtration fraction (GFR) of the post-stenotic kidney increases immediately after PTA from 30 % (before) to 35 % (early after). EHWZ (before 17.6, early after 14.1, late after 10,8 min) and Tmax inversely correlat with GFR. I-131-Hippuran clearance indicates only a late increase (before 306, early after 309, late after 317 ml/min). According to this retrospective study GFR as well as Tmax and EHWZ (partially GFR dependent parameters) are most suitable in the follow up after PTA of a renal artery stenosis.