BACKGROUND:: Cardiac tamponade (CT) as the primary clinical manifestation of lymphomas is extremely rare. Angioimmunoblastic T-cell lymphoma (AILT) is characterised by systemic disease usually presenting with generalised peripheral lymphadenopathy, hepatosplenomegaly, and bone marrow infiltration. CASE REPORT:: We report on a 59-year-old male patient with CT as initial clinical manifestation of AILT. Coexistence with malignant pleural mesothelioma was additionally revealed. Cytologic examination of pericardial fluid presented diffuse lymphoid cells and sporadic malignant mesothelial cells. AILT diagnosis was confirmed by thoracoscopic mediastinal lymph node and bone marrow biopsy. Despite the presence of pleural effusion, the diagnosis of mesothelioma was initially established by cytologic examination of pericardial fluid, due to the patientʼs critical cardiac condition requiring prompt subxiphoid pericardiocentesis. CONCLUSION:: CT as primary clinical manifestation of AILT is very rare. This case reflects the differences in the underlying biology of AILT and consequently the vast spectrum of its clinical presentations. Coexis-tence of AILT with malignant pleural mesothelioma is also extremely rare.