Objective To explore the association of body mass index (BMI) with high-resolution CT (HRCT) volumetric data and HRCT phenotypes in patients with chronic obstructive pulmonary disease (COPD). Methods Sixty-two consecutive COPD patients underwent HRCT and their weight and height were recorded. COPD subjects were classified into three phenotypes based on the visual HRCT findings (with or without emphysema and/or bronchial wall thickening). With the volumetric HRCT data, the total lung volume (TLV) was calculated automatically by Extended Brilliance Workspace^TM , the total emphysema volume (TEV) was obtained by applying density thresholds of -950 HU, and the TEV/TLV was calculated as an emphysema index (EI). The correlation between the volumetric HRCT data and BMI was assessed using Spearman correlation analysis. The three phenotypes of COPD subjects were evaluated using one-way ANOVA. Results Visual HRCT findings showed that the COPD patients were classified into 3 phenotypes: phenotype A (n=42), phenotype E (n=9) and phenotype M (n=11). BMI of COPD patients was correlated with both TEV (r=-0.389, P=0.002) and EI (r=-0.424, P=0.001). COPD patients with phenotype A had a significantly higher BMI (\[23.4±3.4\] kg/m²) compared with those with phenotype E (\[20.6±3.1\] kg/m², P<0.05). The BMI of patients with phenotype M(\[21.3±2.7\] kg/m² ) was not significantly different from those of phenotypes A or E. Conclusion The TEV and EI are negatively correlated with BMI in COPD patients. HRCT phenotype A compared with phenotype B and C is associated with a higher BMI in COPD patients.