Pulmonary artery pseudoaneurysm (PAP) is a rare vascular phenomenon with a high mortality rate, as these entities can enlarge, rupture, and lead to asphyxiation. Pulmonary mucormycosis (PM), an underdiagnosed but an increasingly seen entity in the era of chemotherapy and immunosuppression, is a known cause of PAP, and should be suspected in immunosuppressed patients with hemoptysis. We present a case of PAP due to PM in a patient with recently diagnosed diffuse large B-cell lymphoma of the liver who underwent chemotherapy and developed acute cavitary lung disease and hemoptysis. His diagnosis was delayed due to the withholding of iodinated contrast with computer tomography (CT) imaging in the setting of renal failure. He then underwent embolization of his PAP with resolution of his hemoptysis. PAP is an uncommon cause of hemoptysis that can be diagnosed with CT pulmonary angiography, and mucormycosis is a known but rare cause of PAP in patients with malignancy receiving immunosuppression.