This case report presents a rare case of a 25-year-old female patient with a known history of rheumatic heart disease who developed a pseudoaneurysm of the superior mesenteric artery (SMAPA) after infective endocarditis (IE). The patient presented with chest pain, shortness of breath, and fever, and was diagnosed with IE and severe mitral valve regurgitation (MVR). After receiving appropriate medical treatment for six weeks, the patient developed a vague and dull abdominal pain, initially attributed to septic emboli of the mitral valve vegetations. However, subsequent evaluation revealed a mycotic SMAPA, which was treated with open surgical repair due to unfavorable anatomical characteristics and infectious etiology. This case highlights the importance of maintaining a high level of clinical suspicion of mycotic pseudoaneurysms in patients with risk factors and the importance of using CTA as the gold standard imaging modality for accurate patient evaluation.