This study sought to explore the effects of personalized rehabilitation exercises in the postoperative rehabilitation of breast cancer patients. A total of 93 breast cancer patients admitted to our hospital from January 2018 to December 2019 were taken as research subjects for this study. Based on order of admission, patients were assigned to a control group (46 cases) or an observation group (47 cases). All patients underwent a modified radical mastectomy for breast cancer. Patients in the control group received routine nursing and rehabilitation training after their operations, while those in the observation group received personalized rehabilitation exercises (for a period of 6 months) in addition to the rehabilitation training received by the control group. The immune function indicators, the incidence of upper limb-related complications, the movement of the shoulder joint, upper limb function, ability of daily living (ADL), and quality of life (QoL) was then compared between the two groups before and after the intervention. Patients in the observation group had lower incidences of upper limb edema and subcutaneous fluid than those in the control group (P<0.05). Further, following the intervention, compared to patients in the control group, patients in the observation group had higher CD4+, CD4+/CD8+ levels, lower CD8+ levels, a greater range of motion in their shoulder joints (P<0.05), lower upper limb function impairment scores [based on the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire] (P<0.05), higher ADL scores (P<0.05), and higher QoL scores (P<0.05). Personalized rehabilitation exercises reduced the postoperative upper limb complications experienced by breast cancer patients, improved their immune function, shoulder joint mobility and upper limb function, and improved their ADL and QoL.