An 8-year-old male presented with a cystic lung lesion in the left lower lobe, which was initially detected during surgery for a spontaneous rupture of the sigmoid colon at the age of 6 years. Tissue fragility and a tendency to bleed easily were noted during the surgery, which strongly suggested vascular Ehlers-Danlos syndrome. Although there was no abnormality in the hemostasis screening test, or any suspicious hereditary problem in his pedigree, genetic gene testing for vascular Ehlers-Danlos syndrome was recommended, and showed a de novo mutation in the COL3A1 gene. This report presents the case of patient with occlusive vascular Ehlers-Danlos syndrome accompanying a congenital cystic adenomatoid malformation of lung, in addition to a duplicated infrarenal vena cava.