A 48-year-old asymptomatic woman was introduced to our department because of the detection of an abnormal lung shadow before gallbladder stone surgery. Non-contrast chest-computed tomography (CT) showed an ill-defined area of opacity in the left basal segment. We performed a bronchoscopy that confirmed normal bronchial branching, and revealed no significant findings regarding the shadow. Contrast-enhanced CT revealed an abnormal artery branching from the celiac artery and we diagnosed anomalous systemic arterial supply to the left basal lung. Transection of the aberrant artery and a left basal segmentectomy were performed successfully. This case presented an infiltrative shadow due to historic inflammation, which made it difficult to identify the aberrant vascular shadow. It is necessary to check the inflow of aberrant blood vessels when a funicular shadow is detected in the basal lung segment.