Background: Breast cancer survivors frequently experience shoulder pain and decreased range of motion, making their daily activities more difficult. No previous studies have established the results of bee venom phonophoresis in the treatment of shoulder dysfunction post-mastectomy. Therefore, this work aimed to evaluate if bee venom phonophoresis has beneficial effects on improving the shoulder pain, dysfunction, and range of motion in post-mastectomy patients.  Methods: This randomized controlled trial was carried out between November 2021 and April 2022. Forty female patients aging from 40-to 65 years suffering from shoulder dysfunction 3 to 6 months following modified radical mastectomy were randomly divided into two equal-sized groups: a study group (Group A) who received bee venom phonophoresis with pulsed ultrasound around the shoulder and a control group (Group B) who received pulsed ultrasound around the shoulder only. Three consecutive weeks of three sessions per week were devoted to the intervention program. Patients in both groups received their medical care and selected exercise program (shoulder circles figure, arm lifts figure, wand exercise figure, wall climbing& corner wall stretch).