Abstract Background Pericardial window, in addition to promoting pericardial drainage, can also provide samples of the pericardium for anatomopathological examination. However, such biopsies’ contribution to clarifying the etiology of pericardial effusion has been debated. Objective To analyze the diagnostic value of non-targeted pericardial biopsy obtained from pericardial window procedures. Methods Data from 80 patients who had undergone parietal pericardial biopsies from 2011 to 2020 were retrospectively reviewed. Statistical significance was considered if p < 0.05. Results Fifty patients were male [...]