INTRODUCTION: Upper urinary tract stones are relatively uncommon in Nigeria and they are most often seen in men in their 4th and 5th decades. There is however no recent report on this disease from our locality. This retrospective study was done to evaluate the pattern of presentation of upper tract urolithiasis in our institution. PATIENTS AND METHODS: We reviewed all cases of renal stones referred to a single Consultant in a Teaching Hospital in Southwestern Nigeria over a two year period. RESULTS: Twenty cases of renal calculi presented within the study period. All patients presented with sudden onset of loin or back pain, and the diagnosis was confirmed radiologically. The mean age of our patients was 27 years (age range 13-38 years), and the male to female ratio was 1.5: 1. Nineteen patients (95%) reported poor fluid intake (<1.5L/day), and 17/20 (85%) frequently total fasted totally (no water or food intake) for religious reasons. Serum calcium was normal in 15 of 16 patients (94%) and only marginally raised in the remaining patient. All patients were treated with a high fluid intake (3L/day) and analgesics, and 16 of the patients (80%) passed their stones spontaneously. The other four are currently pain free, one of whom is awaiting surgery. CONCLUSION: This (uncommon) occurrence of upper tract urolithiasis in young adults in Ibadan may be related to chronic dehydration exacerbated by religious fasting. Further studies are required to explore this relationship, PMID: 15287295 [PubMed - indexed for MEDLINE