Left atrium thrombus; This is a literature report.  A 60-year-old female patient received BNT162b2 (BNT162B2), as dose 1, single (Batch/Lot number: unknown) and as dose 2, single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history included: "Chest pain" (unspecified if ongoing); "worsening dysponea" (unspecified if ongoing); "worsening dysponea" (unspecified if ongoing); "systolic heart failure" (unspecified if ongoing); "non-ischaemic cardiomyopathy" (unspecified if ongoing), notes: 3 years ago; "hypertension" (unspecified if ongoing); "hypothyroidisam" (unspecified if ongoing); "tobacco use" (ongoing); "Orthopnea" (unspecified if ongoing); "SARC-CoV-2 infection requiring hospitalisations" (unspecified if ongoing); "lower extremity oedema to her thighs" (unspecified if ongoing); "lower extremity swelling" (unspecified if ongoing); "admitted" (unspecified if ongoing). The patient's concomitant medications were not reported. The following information was reported: THROMBOSIS (hospitalization, medically significant), outcome "recovered", described as "Left atrium thrombus". The patient underwent the following laboratory tests and procedures: Blood creatinine: 1.4 mg/dl; Blood pressure measurement: 160/107 mmHg; Brain natriuretic peptide: 4387 pg/mL; Cardiac telemetry: did not revealed any evidence of atrial fibrillati; Echocardiogram: 2.4*2.2cm well circumscibed LA mass, notes: with an echolucent core and broad-based attachment to the superior retroaortic LA wall; Dilated left ventrical, notes: with normal wall thickness; LVEF of less than 20%, notes: Resolution of LA thrombus; Left ventricular ejection fraction of 20 - 24%; Electrocardiogram: Synus rythum with first degree, notes: atrioventricular block with occasional premature ventricular complexes, left axis deviation, LA enlargement and intraventricular conduction delay; Suspicious for a thrombus; Haemoglobin: 12.7 g/dl; Heart rate: 89, notes: beats/min; Magnetic resonance imaging: 1.9cm low signal intensity LA mass, notes: near the right upper pulmonary vein with evidence of sever slow flow throughout the LA body surrounding the mass; Confirmed thrombus formation; Oxygen saturation: 95 %; Platelet count: 177, notes: K/ul; Respiratory rate: 30, notes: breaths/min; SARS-CoV-2 test: infection; Troponin: 10.10 ng/ml; Venous pressure jugular: elevated; Weight: 10.9 kg; White blood cell count: 7.5 K/ul. Therapeutic measures were taken as a result of thrombosis.  No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.; Sender's Comments: Based on known drug safety profile, there is reasonable possibility of causal association between the event Intracardiac thrombus and BNT162b2. The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.