BACKGROUND: Lower extremity deep venous thrombosis (DVT) is a major complication of hip fracture, which is a common injury in the elderly. We examined the relationship between the preoperative wait period and the frequency of postoperative DVT in hip fractures. METHODS: Fifty-four cases of hip fractures that were treated at the Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital were included. In all these cases, we performed surgery (osteosynthesis or hemiarthroplasty). The patients of group A underwent surgery within 2 days of their injury, and the patients of group B underwent surgery after ≥3 days of injury. In all the cases, we measured serum D-dimer levels 1 week after surgery. We then examined DVT by sonography when the D-dimer levels were more than 10μg/mL and when DVT was strongly suspected based on the symptoms. RESULTS: The frequency of proximal DVT was significantly higher in Group B (Pearson's chi-square test, P=0.019) than in Group A. There were no significant differences between total and distal DVT or in the D-dimer levels in both groups. There were no cases of symptomatic pulmonary embolism. CONCLUSION: The long preoperative period, which was ≥3 days, increased the risk of proximal DVT.