Introduction: Strontium ranelate is a strontium salt of ranelic acid that enhances bone healing by increasing the deposition of new bone-forming osteoblasts and reduces the function and number of bone-resorbing osteoclasts. Strontium ranelate acts via a dual mode of action with both bone-forming and bone-resorbing properties, and may therefore be beneficial in fracture healing. It is therefore promoted as a “dual-action bone agent. Objective: To determine the efficacy of strontium ranelate in the healing of surgically fixed tibial diaphyseal fractures using intramedullary devices (nails) in tertiary care hospital. Material and Methods: This descriptive case series study was done at the department of orthopedic surgery, Chandka medical college Larkana and was conducted for six months between 1st of July 2021 to 31st of December 2021. Total 184 patients with closed diaphyseal tibial fractures were included. All patients have undergone closed reduction and internal fixation using nail. Strontium ranelate as a single dose for a duration of three months was given. Final outcome i.e. efficacy was measured on the basis of clinical and radiological criteria. Descriptive statistics were calculated using SPSS. Stratification was done and the post-stratification chi-square test was applied. P-value ≤ 0.05 was taken as significant. Results: There were 118 were male and 66 were female. The mean age of study subjects was 34.18±9.80 years. The mean duration of fracture was 5.78±3.29 days. 49.5% were caused by fractures due to road traffic accidents. The efficacy of strontium ranelate was found in 67.9%. The significant association of efficacy of strontium ranelate was observed with age and duration of fracture. Conclusion: Significant efficacy of strontium ranelate in the healing of surgically fixed tibial diaphyseal fractures on clinical and radiological assessment was observed.