Children with HIV infection, with or without acquired immunodeficiency syndrome (AIDS), develop nephropathy (HIVN) in 15% of the cases. HIVN is defined as persistent proteinuria for >24-48 hrs without fever in HIV infected children without other demonstrable infection. REnal ultrasonography demonstrates enlarged hyperechoic kidneys. However, there is limited information about radionuclide studies in HIVN. Between 1991 and 1997, 33 MAG-3 renal scans and 33 renal sonograms were simultaneously done in 23 pediatric patients (age 10 days to 14 years, mean 7.4 years)with HIVN. The films were read by independent observer blind folded. The study group was subdivided into group (Grp)1, 12;(mild renal insufficiency (RI), creatinine clearance (CrCl)>50ml/min), Grp2, 6;(moderate RI, CrCl 25-50ml/min) & Grp3, 5;(severe RI(CRF),CrCl<25ml/min). CrCl was calculated using Schwartz formula. Ten normal scans from age matched children were analyzed as controls. Results of quantitative variables and renal sonograms findings were correlated to degree of RI. The variables studied were: size of the Kidneys, time to peak minutes (min), t-1/2 (peak activity in kidneys in min), residual cortical activity (RCA), ratio of original cortical activity (OCA) at 2.5 min and (RCA) at 20 min and kidney to background activity (KD/BKG) at 2 min. All had significant proteinuria (spot urine protein/creatinine>1)& 34% with moderate to severe RI were hypertensive. All patients were hydrated one hour prior to the study and 0.2mCi/kg body weight of MAG-3 was injected as a rapid intravenous bolus (dose range 1mCi-10mCi). Paired student 't' test was used for statistical analysis;p<0.05 was considered significant. All patients with HIVN had significant difference in all the quantitative variables in comparison to (vs.) age matched controls (p<0.00s1). T-1/2, RCA and OCA/RCA was significantly increased in Grp1 and in Grp3 vs. Grp2. RCA, OCA/RCA was significantly incrased vs. controls. Only groups 2&3 had enlarged, echogenic kidneys with loss of either with MAG-3 or severity of RI. Our data suggest that MAG-3 renal scintigraphy is a reliable non invasive marker to assess the presence of HIVN in children with HIV infection and may also be useful in assessing the progress of renal disease in these patients.