Postmortem biochemical investigations in vitreous humor samples collected before and after performing multiphase postmortem computed tomography angiography were performed in the past and demonstrated that specific contrast material injection allowed perfusion and radiological identification of the main vessels of the eye to be obtained without any changes in vitreous humor composition. In the study presented herein, we aimed to test whether the injection of the same contrast material using the same postmortem angiography protocol might influence pericardial fluid composition. Postmortem biochemical investigations were performed on pericardial fluid samples collected from bodies that underwent postmortem angiography (n = 16) prior to and post angiography. Two pericardial fluid samples were analyzed. No statistically significant differences were noticed among levels of any tested markers (urea nitrogen, creatinine, uric acid, C-reactive protein, procalcitonin, beta-hydroxybutyrate, and total IgE levels) in pericardial fluid samples collected prior to and post angiography, leading to the conclusion that pericardial fluid sampling can be delayed until after postmortem angiography when a specific contrast material injection is used.