Continuous renal replacement therapy (CRRT) is used to treat severe acute kidney injury in intensive care units. The aim of this study was to compare two anticoagulation techniques in CRRT, the infusion of dalteparin and regional citrate-calcium anticoagulation, in terms of efficacy and safety. In a retrospective study, we analysed data on 77 dalteparin and 75 citrate-calcium treatment periods. The primary endpoint was the life span of the CRRT circuit. The use of regional anticoagulation with citrate and calcium resulted in a significantly longer CRRT circuit life span as compared to that achieved with dalteparin infusion.