Objective To discuss the application of intramedullary interlocking nail in the treatment of femoral shaft fractures.Methods Retrospective analysis was given to 112 cases of femoral shaft fractures treated with intramedullary interlocking nails from February,1996 to April,2003.Results 98 cases out the 112 were followed up,and they all healed 13 to 26 weeks after operation (average 18.2 weeks)with no complications such as infection,fracture nonunion,break of the nail and others.Conclusions Intramedullary interlocking nail is effective in the treatment of femoral shaft fracture.