There have been increasing studies regarding the influence of body composition on oncological patient outcomes. Terms such as sarcopenia, obesity and sarcopenia obesity have been used widely in present studies about clinical outcomes of oncological patients. Sarcopenia obesity, defined as the concurrence of sarcopenia and obesity, remained unclear in oncological patients. Recent researches have demonstrated that sarcopenia obesity is associated with the occurrence, development and prognosis of carcinoma. Early diagnosis and effective therapy can improve oncological patients’ clinical outcomes. As a consequence, further understanding of sarcopenia obesity is critical to direct better clinical work. This review described the relationship between sarcopenia obesity and adverse clinical outcomes in oncological patient. Of note, oncological patients with sarcopenia obesity tend to be with higher dose-limited toxicity, higher surgical complications and lower overall survival. More attention should been paid on sarcopenia obesity in these patients.