BACKGROUND: Procedural techniques such as dissection and separation of blood vessels or nerves from the tumor for preserving limbs and functions involves high surgical difficulty. We hypothesized the relation of vessel and/or nerve preservation to surgical time and blood loss, accurately reflecting surgical difficulty. In this study, we elucidated the variables affecting surgical time and intraoperative bleeding in patients with malignant soft tissue tumors who did not undergo any reconstruction after tumor resection. METHODS: We included 153 patients with malignant oft tissue tumors in the trunk (n = 72), thigh (n = 68), and upper arm (n = 13) at nine institutions. We analyzed the possible predictive variables affecting surgical time and intraoperative bleeding. RESULTS: Overall, the study included 153 patients (85 men and 68 women) with a mean age of 65 years. The tumors were primary soft tissue sarcoma (STS) (n = 114), local recurrent STS (n = 25), and soft tissue metastasis (n = 14). The median number of participating surgeons was three. The mean and median surgical time were 144.6 and 123 min, respectively. The mean and median intraoperative bleeding were 157.1 and 55 mL, respectively. Tumor size, depth, dissection and separation of blood vessels from the tumor, dissection and separation of nerve from the tumor, and the number of participating surgeons were significantly related to the surgical time and intraoperative bleeding. CONCLUSIONS: The procedure of dissection and separation of blood vessels and nerves from the tumor were related to surgical time and intraoperative bleeding in patients with malignant soft tissue tumors, especially large and deep tumors.