Cystic Fibrosis (CF) is an autosomal recessive genetic disorder characterized by mutations in the cystic fibrosis transmembrane regulator gene. The pathophysiology is based on abnormal chloride secretion from columnar epithelial cells. As a result, patients with CF have symptoms related to their inability to hydrate secretions in the respiratory tract, pancreas, and intestine, among other organs. In the lung, thick, inspissated secretions give rise to chronic obstructive pulmonary disease characterized by severe pulmonary infections, culminating in respiratory failure. Subacute exacerbations of CF lung disease are treated with antibiotics and various forms of chest physiotherapy. When large areas of the lung develop abscesses or necrosis, surgical treatment is often indicated. Options include lobectomy as a temporizing measure and lung transplantation for end-stage CF lung disease. Here, we present an unusual case of a man with CF whose lung function had remained relatively good until adulthood. His left upper lobe became chronically infected and progressively non-functional. Because the patient's overall lung function was moderately preserved, an open left upper lobectomy was performed to prevent recurrences of subacute infections and subsequent damage to the left lung.