In this report, we describe the case of a woman with suspected COVID-19 immunization-induced probable catastrophic antiphospholipid syndrome. The patient is a 35-year-old female with a past medical history significant for antiphospholipid syndrome, not on anticoagulation, who presented with a 5-day history of abdominal pain and distention, nausea, vomiting, and shortness of breath. She had received her first dose of the Pfizer COVID-19 vaccine one day prior to the onset of symptoms. After extensive workup at an outside hospital, she was found to be in acute heart failure exacerbated by severe mitral and tricuspid regurgitation. She was transferred to our hospital for escalation of care. EKG showed evidence of prior inferior and septal myocardial infarction. Transesophageal echocardiogram (TEE) showed reduced ejection fraction, severe mitral and tricuspid regurgitation, and a left ventricular thrombus. Cardiac MRI showed subendocardial late gadolinium enhancement indicative of ischemia. However, CTA of the coronary vessels showed no signs of obstruction. Therefore, her acute heart failure was thought to be due to small vessel thrombosis secondary to antiphospholipid syndrome. During admission, she had several absence seizure-like episodes. CT head showed several hypodensities of the deep white matter and brain MRI demonstrated multiple hyperintense T2 FLAIR signal foci with restriction diffusion and enhancement involving the cerebral hemisphere, consistent with subacute strokes attributed to being secondary to antiphospholipid syndrome or embolic from the left ventricular thrombus. She was treated with heparin for suspected catastrophic antiphospholipid syndrome and high-dose corticosteroid therapy for concomitant Systemic Lupus Erythematosus (SLE). She was discharged in a stable condition.