Abstract Introduction: The goal of any fracture treatment is early union of fracture and to restore the function of the injured extremity completely. This may be achieved by closed reduction and immobilization and different modes of internal fixation. Aims and Objectives: To Study Primary Treatment Modality and Period of Union of Fracture Shaft of Femur and Tibia. Methodology: This study includes retrospective and prospective cases with complex fractures of shaft of femur and tibia admitted at our hospital during the period July 1998 to June 2002. A series of 52 cases of comminuted fractures of shaft of femur and tibia were studied. The study included 21 fractures of shaft femur of which 3 were Grade I compound and 18 were closed and 31 fracture of tibia of which 5 were grade I compound and 26 were closed. Result: In maximum cases 27 (57.69%) primary modality of treatment was POP slab and in 22 (41.30%) cases was skeletal traction was applied. Average operative period was 72 minutes out of 18 cases with operative period more than 90 minutes, 17 were fracture femur and one of fracture tibia. Average period of union was 23.05 weeks for fracture of femur and 17.6 weeks for fracture of tibia By neer’s criteria Excellent Outcome was found in Tibia fracture (83.33%) while Good and Fair in Femur Fracture (10.58%), (26.31%) and Poor outcome was also found in Femur Fracture (5.26%). Conclusion: The technique of minimally invasive plate osteosynthesis is a safe and reliable treatment modality for complex comminuted fracture of femur and tibia. In biological plate osteosynthesis the incidence of nonunion, implant failure is much lower compared to conventional open plating for similar fractures

Keywords: Primary Treatment Modality, Period of Union, Fracture Shaft of Femur and Tibia.