Autosomal dominant polycystic kidney disease (ADPKD) is the commonest congenital cystic renal disease. Factors such as hypertension, urinary tract infection, hematuria, and proteinuria may affect the progression to chronic renal failure in ADPKD patients. Therapeutic interventions, such as the use of angiotensin converting enzyme inhibitors (ACEI) or diet modification, may impact the natural progression of the disease. We aim in this study to review a registry of ADPKD patients in order to compare the slow and fast progressors and identify possible predictors of progression and interventions that slow the progression of this disease. Sheffield Kidney Institute (SKI), one of the largest kidney institutes in Northern Europe, has registered a large number of ADPKD patients since 1981. SKI's computer network contains a wide range of information on these patients. We selected 94 adult polycystic patients from the SKI for retrospective analysis of factors affecting progression to chronic renal failure. Patients who doubled their s. creatinine in < or = 36 months were considered fast progressors (FP), while those who doubled their s. creatinine in > 36 months were regarded as slow progressors (SP). There were 70 patients in the FP group and 24 patients in the SP group. A third group of 137 patients consisted of non-progressors (NP) who had stable s. creatinine levels during the same period. We found that the incidence of hypertension, UTI, macroscopic and microscopic hematuria, and overt proteinuria in the FP group was higher than in the SP and NP groups. Modification of some factors, such as hypertension and UTI, may decrease the rate of the deterioration of renal function.