Oncological research is concerned with developing new substances, new chemotherapeutical combinations, dietetics, psychology, retrieval of data, immunomodulation and accommodation. All these research areas show a conflict between the safety of patients and the retrieval of data. Models for a solution are 1) the exclusion of a not yet established medicine which benefits the interests of patients and 2) the analysis and balancing which covers both approaches without exclusion. Balance is the preferred model because it allows developments which support the safety of patients. What these conflicts consist of and what leads to a solution from an ethical standpoint is discussed in the following issues: vulnerability, informed consent, the principle of equipoise (ratio of preferring interests), data monitoring committees, publication and research in fields of palliative medicine.