This paper compares the effectiveness of normal saline and heparinised saline as a flushing solution in maintaining patencyof arterial catheters. Use of heparin as a flushing solution in maintaining patency of intra- arterial catheters has been a recognizedpractice. Due to its anticoagulation properties, heparin can cause side effects like heparin-induced thromhocytopenia in hypersensitivepatients. The alternative, normal saline solution increases the accuracy of patients' coagulation status and enhances safer clinicalpractice. A systematic search was conducted at Cochrane Library, Medline, CINAHL, OVID and Joanna Briggs Institute. Reviewperiod covered from 1990 to 2011. Methodological validity of included studies was evaluated using SIGN grading checklists fromScottish Intercollegiate Guidelines Network. There is inconsistent evidence and sample sizes were too small to allow statisticalsignificance to be achieved. Meta-analysis was performed for 2 studies; results revealed that heparinised saline offers no addedadvantage over normal saline. There is insufficient evidence to support the use of heparinised saline for flushing arterial catheters. Arigorous research design is needed to determine variables known to influence patency of arterial catheters. Sound clinical judgementmust be exercised in situations that require the need of heparinised saline.