The purposes are to assess the problems associated with intravascular imaging methods such as angioscopy and intravascular ultrasound (IVUS) and to evaluate their efficacy through the results of our observations. A total of 54 limbs in 53 patients, 50 patients with chronic venous insufficiency and 3 patients with deep vein thrombosis, were diagnosed and operated on using angioscopy (Olympus OES, order made type) and IVUS (Endosonics, model 82700). The imaging catheters were inserted through a branch of the long saphenous vein and the valves and the intraluminal views were observed. By angioscopy, intraluminal views were clearly observed in 98% of all lesions. However, observation became more difficult in iliac veins compared to in femoral and in long saphenous veins (p < 0.01). Venous wall and thrombus were detected more by IVUS than by angioscopy (p < 0.01), but only 21 valves (24%) were visualized by IVUS among the 88 valves observed by angioscopy. The intravascular imaging method of angioscopy is more suitable for observing valves and intraluminal views compared with IVUS, whereas IVUS is more suitable for observing the cross-sectional venous wall.