Background: Many complications may occur after modified radical mastectomy (MRM) such as restricted shoulder mobility, wound infection, seroma formation, pain and lymph edema. Purpose: To find the correlation between shoulder flexion and abduction range of motion (ROM) with upper extremity disability and quality of life in female post MRM. Methodology: A cross section observation study was conducted in a tertiary care hospital. A total of 20 breast cancer survivors who underwent MRM before 6 months or more were included. Their affected side shoulder flexion and abduction ROM was measured using universal goniometer, upper extremity disability was assessed using Upper Extremity Functional Index (UEFI) and Quality of Life was assessed using WHOQoL-BREF questionnaire. Results: Karl Pearson’s correlation coefficient was used to find the correlation. Strong positive correlation was found between shoulder flexion ROM and UEFI score, physical, psychological and environmental domains, whereas moderate positive correlation was found between shoulder flexion ROM and overall QoL, these were statistically significant (p<0.001). But there was weak positive correlation found between shoulder flexion ROM and social domain of WHOQoL-BREF which was statistically not significant (p>0.001). Further strong positive correlation was found between shoulder abduction ROM and UEFI score, overall Qol, physical and psychological domain and moderate positive correlation was found between shoulder abduction ROM and environmental domain whereas again weak positive correlation found with social domain which was statistically not significant (p>0.001). Conclusion: Decreased shoulder ROM can increase upper extremity disability and affect overall QoL in breast cancer survivors post MRM. Keywords: Breast cancer survivors, Modified Radical Mastectomy, Quality of Life, Shoulder ROM, Upper extremity disability.