Clinically, it is difficult to predict deep vein thrombosis (DVT), but the in vitro saline dilution test using the Thrombo-elastograph (TEG) is reported to identify the risk for individual patients [1]. The Biobridge Impedance Clotting Time (ICT) is more sensitive and reproducible than the TEG [2], and we therefore studied 33 patients undergoing elective laparotomy to see if pre-operative saline dilution tests using both the TEG and ICT predicted post-operative DVTs. Post-operatively, both legs were scanned daily for 7 days using 125I Fibrinogen to detect DVTs.The mean age of the patients was 65.7±2.4 years and 17 had malignant disease. In this clinically high risk group, 24 developed a DVT.Fifty-one percent were predicted correctly by TEG. The ICT was significantly better as a predictor with 79% of all patients correctly predicted (p<0.01).The saline dilution test using the ICT is a significant improvement on the TEG, and may enable us to tailor DVT prophylaxis policy to each patient’s specific requirements.Heather BP, Jennings SA, Greenhalgh RM. The saline dilution test - a preoperative predictor of DVT. Br J Surg 1980; 67: 63-65Blair SD, Menashi S, Samson D, Greenhalgh RM. Can the hypercoagulability of surgery be measured? Br J Surg 1986; 73: 500.