Purpose. We aimed to evaluate the potential for implementing exercise interventions for patients with breast cancer in the Netherlands, based on findings of the Dutch randomized controlled trials in this population. Methods. We evaluated the implementation of four Dutch exercise trials retrospectively, using the five dimensions of the RE-AIM framework: Reach (exercise participation rate), Effectiveness for physical fitness, fatigue, quality of life, and physical function, Adoption (e.g., satisfaction of physical therapists guiding the exercise intervention), Implementation (cost-effectiveness and exercise adherence correlates thereof), and Maintenance (maintenance of exercise levels by individual patients and sustainability of exercise delivery at organization level). Thereby, we reflect on these results using (international) literature to gain better insight in overall barriers, facilitators, and opportunities for further implementation of exercise interventions. Results. Participation rates of 44-52% not only indicated acceptable Reach in the context of a trial but also indicated room for improvement. Effectiveness of exercise during and after treatment was demonstrated in most trials showing benefits for aerobic fitness, physical fatigue, quality of life and physical function, and high patient satisfaction. Adoption of the exercise interventions by physical therapists was adequate (satisfaction score: 7.5 out of 10). Evaluation of Implementation indicated adequate adherence to supervised exercise, inconsistent findings on potential correlates of adherence, and promising results on cost-effectiveness. Currently, reimbursement for exercise programs is lacking. Maintenance of intervention effects at the patient level was limited and inconsistent. Maintenance of intervention availability at the organizational level was facilitated by an extensive network of specially trained physical therapists, but better communication and collaboration between different healthcare professionals are desired. Conclusions. ...