For many years, research in the field of psychosocial oncology was dominated by observational and descriptive epidemiologic studies. These were important for identifying and estimating the prevalence of significant psychosocial problems and needs experienced by cancer patients, cancer survivors, and their families. More recently there has been a significant shift toward the development and rigorous testing of behavioral and psychosocial interventions in cancer care. The strongest evidence of the efficacy of such interventions is generated by randomized controlled trials (RCTs), surpassed only in potential impact on practice by high quality systematic reviews and meta-analyses. In this presentation, I will provide several recent examples of successful RCTs of such trials in primary breast cancer. The first study evaluated the effect of cognitive behavioral therapy, physical exercise, or a combination of these two interventions on menopausal symptoms, body image, sexual functioning, psychological well-being, and health-related quality of life in patients with breast cancer who experienced treatment-induced menopause. The second trial investigated the efficacy of a low-intensity, home-based physical activity program and a moderate- to high-intensity, supervised resistance and aerobic exercise program in maintaining or enhancing physical fitness, minimizing fatigue, enhancing health-related quality of life, and optimizing chemotherapy completion rates in patients undergoing adjuvant chemotherapy for breast cancer. I will also touch on issues surrounding the implementation of evidence-based interventions in clinical practice.