He is particularly interested in hereditary susceptibility to these tumours and in lifestyles that increase the risk of tumours. In addition, he investigates the role of these factors on cancer-specific prognosis. The research is often conducted on a very large scale, involving thousands of participants.

For the purpose of this research, large biobanks have been set up, containing the blood of thousands of patients with cancer and, as reference material, the blood of 10,000 citizens of Nijmegen.

Kiemeney is a member of the Scientific Council of the Norwegian Cancer Society. He is also board member of the Research Foundation of the European Association of Urology and board member of the Radboud Fund.