Abstract: Objective To observe the effect of perivenous support with autologous pericardium on neointimal thickening in canine vein grafts. Methods An autologous pericardium graft of 7 cm×4 cm was harvested in right anterolateral thoracotomy. Two equal segments of the jugular vein were transplanted to both sides of the femoral arteries in 12 dogs, and on one side of the vein graft, perivenous support with autologous pericardium was applied. The vein grafts were harvested 2 and 4 weeks after operation and the thickness and area of the neointima calculated using computerized image analysis system. Scanning electron microscopy and PCNA immunohistochemistry were also performed. Results The thickness and area of the neointima were significantly greater in the control grafts than in the grafts with perivenous support (P<0.05), and the proliferation of vascular smooth muscle cells in the supported graft was less active (P<0.05). Electron microscopy showed extensive destruction of the endothelium in the control graft, but only slight damage was found in the graft with perivenous support. Conclusion Perivenous support of the vein graft with autologous pericardium can reduce intimal and medial hyperplasia in the graft.