In a previously reported study we compared the use of a low-molecular-weight heparin (LMWH) and conventional heparin in the thromboprophylaxis of patients with hip fracture. In an attempt to establish additional factors which could aid in predicting the development of deep-venous thrombosis (DVT), we retrospectively studied several clinical and laboratory variables and found that granulocyte count on admission was higher in patients without subsequent postoperative DVT. Forty additional patients were included in a further prospective study in order to validate our previous findings. 38% of patients who developed DVT had a granulocyte count lower than 9,500/microliters, whereas only 18% of those patients with DVT had a count higher than 9,500/microliters. These figures imply a positive predictive value of 38% and a negative predictive value of 82%. We suggest that granulocytes could play a role in the development of DVT and preoperative granulocyte count may be used to detect a high-risk population for DVT after a hip fracture.