Background and Objective: In patients older than 65 years of age, fractures of the Proximal humerus are the second most common in incidence pertaining upper extremity fracture and are only the third most overall common fracture, after hip fractures and the distal radial fractures. It is well known that Most of the minimally displaced fractures of proximal humerus can be treated conservatively. For displaced fractures, many surgical techniques have been described but no single technique is considered to be the standard care. Optimal reduction and fixation of three and four part fractures of proximal humerus remains a challenge well known. Also in most of the surgical techniques and conservative treatments of proximal humerus fractures, post-operative stiffness due to long periods of immobilization remains a challenging issue, even after fruitful union of the fractures. Our study was undertaken to evaluate the functional outcome of the proximal humerus fractures treated with JESS fixators followed by early range of motion exercises post operatively, to curtail the occurrence of stiff shoulder due to longer immobilization periods of other fixation modalities. The final results of the study was then compared to the data of retrospective studies of different modalities of treating proximal humerus fractures and the incidence of frozen shoulder in their studies. Method: It was a Prospective study of 12months duration including 50 adult patients (>18 yrs) with fractures of the proximal humerus admitted to Hospital, and treated by Joshi’s External Stabilization System(JESS) with early mobilization and start of range of motion and pendulum exercises, from post op day 3. Consequently the patients were evaluated till 2 month post-pin removal period, using Murley shoulder score at the time of Pin removal followed by a gap of two months and were followed up at the outpatient clinic. Results: 50 patients were included in the study. The study had 15 (30%) females and 35 (70%) males. out of total 50 cases 18 (36%) patients had left side involvement and 32 (64%) had right side involvement. In 20 (40%) patients the injury to surgery interval was 1-3 days, in 15 (30%) patients the injury to surgery interval was 4-7 days and in 15 (30%) patients the injury to surgery interval was more than 7 days. Neer’s classification was used for classifying the proximal humerus fractures in our study and 3 part fracture was the most common followed by 2 part fracture. Murley score 2 months after implant removal in relation to final outcome was 50.50 ± 5.62 days in excellent outcome group, 55.65 ± 5.69 days in good outcome group, 64.27 ± 7.93 days in fair outcome group and 71.00 ± 11.27 days in poor outcome group. As the duration of complete pin removal increased the final outcome shifted from excellent to poor. Conclusion: In our study we found that proximal humeral fractures can be satisfactorily treated with JESS fixator which is a simpler and affordable method of proximal humerus fracture fixation, which also provides easy early shoulder mobilization and good gain of functionality in about four months since injury. Early mobilization and proper follow-ups with scheduled exercise regimes are of pivotal importance in bringing a better functionality and to decrease the post-operative incidence of frozen shoulder and these factors can be achieved by our modality.