The remuneration of study physicians/investigators in clinical studies is based on the services rendered and is to be adjusted according to the AMG, BfArM or PEI, VFA recommendations, FSA code and the professional code of conduct for physicians. In order to avoid suspicion of corruption, the separation principle (fees are not influenced by ongoing business), transparency principle (disclosure of grants), equivalence principle (service is based on consideration) and documentation principle should always be implemented.