In his research, Roel Bennink focuses on nuclear gastroenterology: gastrointestinal motility, inflammatory bowel diseases and oncology. He plays an important role in the development of new innovative applications and techniques. Currently, Bennink is focusing on regional liver function scintigraphy, research involving the injection of a radioactive tracer that is selectively absorbed by the hepatocytes and is used for the determination of future remnant liver function in patients requiring major liver surgery.

As a professor, Bennink will focus on the Radiology degree programme, specialising in the integration of radiology and nuclear medicine. This involves radiologists and nuclear medicine physicians (future nuclear radiologists) sharing each parts of each other's disciplines and reinforcing one another, resulting in the practice of molecular radiology. Bennink will also play a role in modernising the teaching of nuclear medicine and molecular radiology to students of medicine and the positioning and integration of imaging with regard to the training of doctors.

Bennink has worked at AMC-UvA as a nuclear- medicine physician since 1998. In addition, he has been the director of the nuclear medicine residency programme since 2011 and a deputy director in the radiology residency programme since 2015. In 2017, he became president of the Concilium Radiologicum: the integrated residency board of the NVNG (Dutch Society of Nuclear Medicine) and the NVvR (Radiological Society of the Netherlands). Bennink is also a member of the advisory council of the Amsterdam Gastrointestinal Oncology Centre (GIOCA), part of AMC-UvA. He is vice-president of the NVNG and national delegate to the Association of Nuclear Medicine (EANM) and the European Union of Medical Specialists (UEMS).