Introduction: Loss of kidney function can be sudden, which is called acute kidney injury, or gradual, which is then called chronic kidney disease. Hemodialysis means a procedure that replaces the renal function of blood purification, and it is performed in extracorporeal circulation through a dialysis filter. The goal of the research is to examine which route of administration of nadroparin has a better anticoagulant effect and to examine whether the administration of nadroparin in a venous line in a dose reduced by about 30% has a better anticoagulant effect than the administration of nadroparin in an arterial line. Subjects and methods: The research was conducted during three months in the Hemodialysis Unit of the Pula General Hospital. In the first phase, nadroparin was administered in the arterial line, in the second phase in the venous line and in the third phase in the venous line in a reduced dose by about 30%. The data were collected from the medical documentation, i.e. the record of the patient's dialysis treatment. Results: The proportion of subjects with a clean filter who received nadroparin intravenously was 71.3% and was statistically significantly higher than the 61.6% of subjects who received nadroparin intravenously. 76.6% of patients who received nadroparin intravenously had a clear venous drip, while this was the case in two thirds of patients who received nadroparin intravenously. A clear filter appeared in 77.5% of the treatments in a reduced application in the venous line by about 30%, while in the application in the arterial line it appeared in 61.6% of cases. Every fourth out of five subjects (80.2%) had a clean intravenous dropper when administered into a venous line in a reduced dose by about 30%, while two-thirds (67.7%) of subjects with an application into an arterial line had this the presence of venous drip clots was recorded in 28.75% of cases. Conclusion: In order to improve the quality of hemodialysis patients, research is needed that will help to see which method of administering low molecular weight heparin is the best for each patient.