The research aim was a retrospective analysis of long-term follow-up in patients with an episode of ARF treated during the years 1991-2005, at the Chair and Department of Nephrology of the University Hospital in Cracow. Detailed aims led to defining the most often occurring forms of ARF, mortality analysis- as well as its’ causes in the studied group of patients during the hospital course of acute symptoms, dialysis treatment and with the period after discharge from the Clinic. Afterwards, the cause of renewed treatment with renal replacement therapy after the first episode was also analyzed. The usefulness of selected scales that evaluate the severity of patients clinical state in respect to long-term prognosis and relationship between amount of diuresis and long-term prognosis was analyzed. The degree of patients’ renal impairment before, during and in the post-discharge period of ARF was traced. It was measured as eGFR and/or as concentrations of selected serum markers influencing mortality and the requirement of renewed dialysis treatment in the observed period.