Efforts for international harmonization have made it clear that Japan is far behind in Western countries in all aspects of infrastructure for clinical trials. The introduction of ICH-GCP, 1998, has promoted the rapid growth of infrastructure for investigational new drug (IND) trials; however, the infrastructure for academic cancer trials has shown no remarkable progress. There is still no governmental regulation, no agency for quality control, and no quality assurance audit system even in government-sponsored trials. The author introduces the quality control systems in cooperative groups in Western countries, such as the Southwest Oncology Group (SWOG), National Surgical Adjuvant Breast and Bowel Project (NSABP) and European Organization for Research and Treatment of Cancer (EORTC), and the quality assurance systems by the National Cancer Institute-Cancer Therapy Evaluation Program (NCI-CTEP). Key activities for quality control in cooperative groups are in-house monitoring, site visit audits, institutional performance evaluations and case report form review by study coordinators. NCI-CTEP oversees cooperative group activities through protocol review, supervision of site visit audits and a monitoring committee. Cancer cooperative groups in Western countries have taken the initiatives in advancement of trial methodology and establishment of clinical trial infrastructure. In order to improve the quality of clinical trials, there is need to invest cancer cooperative groups, thus strengthening the activities for overall clinical trials.