Background: Chemotherapy drugs treat cancer by destroying the body’s rapidly proliferating cells; as a result, they do not only affect the cancer cells but also have a variety of negative side effects on non-target tissues, including marked effects on the immune system that make it difficult for the body to fight infection. Objectives: The major cause of the current academic work is to investigate the possible outcomes of aerobic training combined with diet protocol on the immune system in breast cancer cases receiving adjuvant chemotherapy. Design: An open-label randomized control study. Setting: Outpatient setting. Participants: 60 female breast cancer cases were randomly sub-categorized into three groups and given adjuvant chemotherapy. Group (A) performed aerobic exercise and adhered to a special diet protocol; Group (B) only followed the diet plan; and Group (C) only performed aerobic exercise. Intervention: The duration of each treatment intervention was 12 weeks, with each group receiving two sessions each week.