Aim of the study: Determine the effect of early rehabilitation on pain and disability of the shoulder after modified radical mastectomy.

Patients and method: A quasi-experimental research design was utilized in this study. It was conducted in the general surgery wards, oncology and general surgery out patient clinics at Assiut University Hospital and South Egypt Cancer Institute. A convenient sample of sixty adult female patients scheduled to undergo MRM, their ages ranged from 20 to 65 years. They were divided into 2 equal groups; the first was the control group which comprised 30 patients and exposed to routine hospital care only, the second was the study group and included 30 patients and they received early rehabilitation.

Tool: Knowledge assessment questionnaire, Observation checklist, and Shoulder pain and disability questionnaire.

Results: There was statistical significant difference between study and control group regarding pain and disability in the shoulder after MRM before discharge and after 3 months from application of early rehabilitation.

Conclusion: Teaching and applying early rehabilitation significantly improved the shoulder condition of patients in the study group regarding pain and disability of the shoulder.

Recommendations: Nurses working in the general surgery department must apply early rehabilitation in care and follow-up protocols of patients undergoing MRM and use the validated shoulder pain and disability questionnaire.