Proximal humerus fractures are common injuries occurring both in younger and older population. They have a close association with injuries to the axillary nerve injuries which can occur due to both traumatic and iatrogenic causes. Our study was an attempt to determine the incidence of axillary nerve injuries in three and four-part proximal humerus fractures using pre-operative and post-operative nerve conduction studies. A total of 30 patients were included in the study. The patients on admission underwent a pre-operative EMG and NCV study to detect presence or absence of post traumatic axillar nerve injury. The patient then underwent a surgical procedure and fixation type was decided according to the fracture pattern. Post operatively the patient underwent another EMG and NCV study to detect presence of any iatrogenic axillary nerve injury. The patient was then followed up at regular intervals to detect the time taken and degree of nerve recovery achieved. The youngest patient involved in this study was 18 years old and the oldest was 84 years old. The commonest age group that got affected was 55- 64 years. Maximum number of patients were above the age of 50 years. There was no single gender preponderance in this study, with 50% involvement of each gender. The most common mode of injury was fall from height followed by a road traffic accident. The most common type of fracture seen was a three-part proximal humerus fracture and the least common was a 4-part fracture dislocation. In our study the incidence of traumatic axillary nerve injury was 16.7% and the incidence of iatrogenic axillary nerve injury was 26.7%. Out of the 13 patients who developed axillary nerve injury all the patients had partial or complete recovery of nerve function with a good shoulder strength and range of motion. The importance of nerve conduction studies and electromyography as tools for the precise diagnosis of nerve lesions cannot be undermined in such instances. The presence of axillary nerve injuries affects the functional outcome of the shoulder and hampers the return of normal range of joint movements. Even though nerve injuries are present majority of them are neuropraxia or axonotmesis which recover over a period of time with adequate rehabilitation and rigorous physiotherapy programs.