The aim of this study was to determine the incidence of associated urological and non-urological anomalies as well as the renal outcome in patients with a congenital solitary func-tioning kidney (CSFK). A retrospective review of 30 consecutive cases of CSFK seen at the pediatric renal service at the Jordan University Hospital between 2004 and 2008 was performed. There were 20 males and 10 females, whose ages ranged from five days to 14 years. In 20 patients (67%), the left kidney was absent. Associated anomalies were detected in 23 (77%) of the 30 patients; urological anomalies accounted for 47% (14/30) and non-urological anomalies were found in 19/30 (53%) patients. The latter included anomalies of the ear, nose and throat (ENT) in 9/30 (30%), musculoskeletal system (one with hypermobile joints) in 8/30 (27%), gastrointestinal (GI) in 7/30 (23%), cardiovascular (CV) in 4/30 (13%) and dermatological with epidermolysis bullosa, endocrine (euthyroid goiter) and gynecological (cervical cyst) in one patient each (3%). Proteinuria was seen in 6/30 (20%) and hypertension in 2/30 (7%) patients. Chronic renal failure (CRF) was seen in 6/30 (20%) patients, of whom three had end-stage renal failure (ESRF). CRF was seen mainly in patients with more than two associated urological anomalies. Idiopathic hyperuricosuria was found in five of the six tested patients (83%). In our study, the most common associated anomalies with CSFK were urological. The presence of more than two associated urological anomalies increased the risk of CRF.