Ipsilateral fracture of the femur and tibia is also called “floating knee”. And it is well known that its treatment is difficult and functional result is poor in most cases because it has often comminuted, open fracture with severe soft tissue injuries. Authors reviewed 20 cases in 18 patients which were treated from September 1989 to March 1993. All were followed for more than one year. The results were as follows: 1. Among 20 cases of femoral fracture, 15 cases were treated with internal fixation and others with external fixation and among 18 cases of tibial fracture(2 amputations excluded), internal and external fixation were equal in number. 2. The bony union time was shorter in the intramedullary nailing than the plate and screws, and external fixations. 3. The end result was better in Group I(internal fixation for both fracture) than Group II (one or both fractures were treated with external fixator) because the femur had less severe comminution, and soft tissue injuries. 4. There were many complications in Group II than Group I, That is, wound infections, delayed union or non-unions. There were 11 operations for the treatment of complications,.