This article presents the current status of the implementation of clinical cancer registration across all German federal states that started in 2013 and that is basis for setting up comprehensive clinical and population-based cancer registries (CRs). A nationwide definition of relevant cancers, a common model of passive registration, a standard basic set of data items as well as a sustainable funding are prerequisites for a standardized collection of cancer data in Germany. For the collected information, the tools and methods used for data collection and processing, for statistical analyses and reporting, the potential synergies of a comprehensive CR implementing the tasks of both a clinical CR and a population-based CR become evident. Many different tasks of clinical and population-based CRs have already been implemented in Germany. This includes usage of individual patient data for quality assurance and the certification of cancer centers or comparative analyses on the adherence to guideline recommendations. CRs further provided unselected data on the cancer burden in the underlying populations and actively contribute in a variety of ways to many collaborative research projects on cancer etiology, the effectiveness of screening programs or cancer care, or provide patient or outcome data for clinical or population-based studies. Although many tasks of clinical and population-based CRs have already been implemented, a number of great efforts still lay ahead. Major challenges include the harmonization of data collection, the development of required standards and methods for data processing and usage, but first and foremost, the collection of complete and valid data for the different tasks of comprehensive CRs.