Background/Aims: The so-called volume/outcome relationship postulates that a higher caseload and specialization results in an improved outcome. The existence of such a relationship, however, is still debated in the literature. The objective of this review is to discuss the available data on this relationship in surgical oncology. Methods: A Medline analysis was performed using the following terms: volume, outcome, cancer, and surgery. The bibliography of each relevant article was screened for further studies. Results: For most malignancies a volume/outcome relationship was demonstrated in recent years. Components of this improved outcome are decreased perioperative morbidity and mortality, higher quality of life after surgery, improved economic outcome, and a better long-term prognosis for patients with cancer. The magnitude of this relationship, however, varies greatly among different malignancies. The exact reason for the volume/outcome relationship is still unknown. Conclusion: Concentrating high-risk procedures in high-volume hospitals might prevent thousands of perioperative deaths per year. This concept seems feasible for rare and high-risk diseases; however, it is unclear what threshold should be used for the definition of a high-volume provider. For common and low-risk diagnoses, it seems more realistic to educate the medical community in order to improve the outcome for the patients.