Bronchopulmonary segments are subdivisions of lung lobes and provide detailed description of lung anatomy. They are used in surgical resection planning and airway disease quantification. In this paper, we present a method for determining lung segments in volumetric high-resolution CT (HRCT) using segmental bronchi. The bronchial tree is automatically segmented and manually corrected to ensure optimum accuracy. The bronchopulmonary segments are determined by a 3D volume growing with a novel surface smoothing algorithm. Using the detected bronchoplumonary segments of three normal subjects, we measure the inter-patient variation of position of the segments in three subjects.