It is difficult to cure severe open fractures of the lower extremities due to the frequent occurrence of severe damage to soft tissues or blood vessels, as well as bone defects, and concomitant infection, such as osteomyelitis. If appropriate treatment is not performed, long-term complications, such as nonunion of the bone, intractable ulcers, or other disorders, may arise. Between 1993 and 2010, we reviewed the records of 27 patients, and 28 limbs were treated. A total of 31 free-tissue transfers were performed on these 28 limbs. In this study, we classified the degree of damage based on the operative appearance of the condition of the recipient vein. A state that was normal or near-normal was described as type I-normal. A vein that was buried under a scar, but was comparatively easy to detach and retained a moderate adventitia was classified as type II-moderate. A vein with close adhesion between the wall and the scar that was not easy to detach was described as type III-severe. We also examined the relationships between recipient vein type and each of the following: (1) concomitant injury, (2) bone reconstruction, (3) preoperative infection, (4) length of time from injury to reconstruction, (5) eventual reoperation, and (6) flap necrosis. The results showed that there was a statistically significant relationship between recipient vein type and each of the following: bone reconstruction, preoperative infection, eventual reoperation, and flap necrosis. The selection of recipient vein is a factor that greatly affects the outcome of reconstruction of open fractures of the lower extremities. It is important to preoperatively estimate the condition of recipient vein even though it is difficult to preoperatively assess the condition. In some cases, only recipient veins in poor condition can be found intraoperatively on the affected leg. Under such circumstances, a cross-leg flap or a vein graft should be performed without hesitation to use recipient veins in a better condition.