There were 201 cases in peripheral arterial disease at Severance Hospital who were treated between March, 1980 and December, 1989. 1. The incidence of peripheral arterial disease were as follows:Buerger's disease was reported in 147 cases (73%), arteriosclerosis obliterans in 43 cases (21%) and aortoiliofemoral occlussive disease in 11 cases (5.4% ). 2. In 144 cases (97.9%) of Buerger's disease, it was involved in the lower extremities. The most common obstructive site of Buerger's disease was the popliteal artery in 51 cases (48.2% ). 3. Among 147 cases of Buerger's disease, male and female ratio was 75 to 1 and peak incidence of age was between 30-40 year of age. 4. Thirty-five cases of Buerger's disease had experienced operative treatment previously and 140 cases of Buerger's disease were smoker. 5. Lumbar sympathectomy was performed in 70 cases of Buerger's disease and amputation was performed in 43 cases (60%). Transient symptomatic improvement was noticed. 6. The Doppler ultrasound flow meter not only helps diagnose the disease but also is a very useful method to objectively assess the severity of the initial symptoms and postoperative results in Buerger's disease. 7. The average age of arteriosclerosis obliterans was 50.6 year of age and it was less than one year that 18 cases of the all have the duration of disease. 8. Twenty-four cases of arteriosclerosis obliterans had experienced operative treatment previously. Ten cases had diabetes mellitus. 9. Conservative treatment was performed in 35 cases of arteriosclerosis obliterans and symptomatic improvement was not noticed. 10. Aortoiliofemoral occlussive disease was in 11 cases and male was 9 cases (81.8% ). 11. The symptoms of the aortoiloiofemoral occlussive disease were coldness (11 cases), claudication (11 cases), skin color change (6 caes), skin necrosis (5 cases) and impotence (2 cases). 12. Diagnostic method such as angiogram illustrated the disease pattern:Type I, Type II and Type III. Endarterectomy was done in 4 cases, by pass graft in 6 cases and percutaneous angioplasty in 1 case. There were one case of wound infection and one case of amputation as postoperative complication.