Quantitative study that aims to characterize patients on hemodialysis according to socio-demographic and identify the main causes of hospitalization in 2007. Data collection was performed in a clinic Guarapuava, Paraná, Brazil, with 29 patients,through medical records and the computerized program Nefrodata, specific to dialysis centers. The medical records were analyzed with the use of descriptive statistics, where 58.7% were male, 62% married and the average age was 53.7 years. As to the underlying diseases, there was a predominance of diabetic nephropathy with 31.1% and 11.8% with hypertensive crisis among the causes of hospitalization. These causes are mostly related to renal disease itself and necessary guidelines and multidisciplinary team interventions focused on treatment of chronic renal insufficiency and adherence to therapy, aiming to reduce and even prevent these hospitalizations.