Abstract This workshop aims to provide an overview on the current state and on selected results of the German National Cohort (NAKO) - the largest multidisciplinary, population-based cohort study in Germany. The session will include one overview presentation and three presentations on selected topics: use of secondary and registry data, environmental exposures, and COVID-19. NAKO aims to investigate the development and aetiology of diseases, and to identify risk factors and enhance early detection and prevention of diseases with a focus on diabetes, cancer, cardiovascular, pulmonary, neurological, psychiatric, and infectious diseases. Between 2014 and 2019, 205,415 participants aged 20-74 years were recruited and examined at 18 study centres across Germany. During their visit to the study centre, they participated in an extensive examination programme including a face-to-face interview, self-administered, computer-based questionnaires, in-depth biomedical examinations, and the collection of various bio-samples. In addition, a subgroup of 30,861 participants received whole-body Magnet Resonance Imaging (MRI) with a focus on brain and cardiac structures, the musculoskeletal system, and body fat distribution. All study participants are re-invited for examinations at the study centres at 4-5 year intervals. The programme for the first re-examination is similar to the baseline programme to detect changes in risk factor profiles and in vascular, cardiac, metabolic, neurocognitive, pulmonary and sensory function. By 31.03.23, 100,822 participants were re-examined, including 14,950 with MRI re-examination. A third examination will start in 2024. Additional information on morbidity, drug use, health care utilization, rehabilitation, cancer diagnoses and therapies, as well as employment and occupational history is obtained by record linkage with secondary data from health insurance companies, the statutory pension insurance, the unemployment fund, as well as through cancer registries and mortality follow-up. Information on environmental exposures (e.g., air pollution, traffic noise, climatic conditions) is linked to residential addresses of the participants to analyse the association with health and development of chronic diseases and to elucidate long-term effects of environmental stressors on health and disease. Two supplemental questionnaires focusing on COVID-19 pandemic-related aspects were provided to all NAKO participants. The second COVID-19 questionnaire was offered online between October 2022 and February 2023 and included questions on general state of health, psychosocial factors, Sars-CoV-2 and long-/post COVID symptoms. It was completed by > 110,000 NAKO participants. Due to its large sample size, the broad examination programme and the longitudinal design, NAKO provides a valuable resource for epidemiologic research and international scientific cooperations. Key messages • The workshop provides information on current state, and selected results of NAKO to facilitate harmonization of data collection between cohort studies and cooperations between scientists. • The workshop will be informative for researchers aiming to work with NAKO data as data access within the European Union is expected to be possible by the end of 2023.