Purpose Interdisciplinary tumor boards are periodical conferences, where optimal individual therapy plans are developed among medical experts with different specializations. The presence of a board-certified radiologist is medically indispensable in almost all relevant boards. In order to systematically evaluate the current workload for radiologists caused by these boards, we evaluated the current situation within German radiology to obtain numbers for future personnel planning. Materials and methods We performed an online survey. We invited all 33 German university chairmen and 50 randomly selected head physicians of radiology at level 3 hospitals to participate. Results We had a participation rate of 79% (26/33) at university hospitals and 56% (28/50) at of level 3 non-university hospitals. The average total number of tumor boards was 3.3/day or 16.7/week at university hospitals and 2.6/day or 13/week at level 3 non-university hospitals. We calculated an average time considering preparation and execution as well as the average number of boards of 33.1 & x202f;h/week for university hospitals and 18.2 & x202f;h/week for level 3 hospitals. This results in a 78.8% workload for a board-certified radiologist at a university hospital (regular weekly work time 42 & x202f;h) and 45.5% work load for level 3 hospitals (regular weekly work time 40 & x202f;h). Conclusion "Speaking radiology" as in interdisciplinary tumor boards represents a fundamental matter of course in radiology. The active participation in boards accomplished by radiologists improves evidence-based patient care. However, given the prevailing scarcity of resources in medicine, the data collected here regarding personnel costs for clinical radiology for participation in tumor boards must be taken into account in future discussions on personnel compensation.