The aim of this study was to assess the long-term functional outcome of vein sparing varicose vein surgery using handheld Doppler ultrasound (HHD). The series consisted of 171 consecutive day-case surgery patients operated on for uncomplicated lower limb varicose veins. Venous segments considered competent were spared based on clinical examination and HHD, which was performed preoperatively only when deemed necessary by the surgeon. After a mean follow-up of 8 years all patients were examined, a systematic HHD evaluation was performed, and the findings were classified according to the CEAP (Clinical, Etiological, Anatomical, Pathophysiological) classification, and disability scoring was performed. During the follow-up period 17% of the legs were reoperated or scheduled for reoperation. At follow-up 79% of all patients were asymptomatic without reoperation. In 24%, recurrent varicosities were present and venous reflux was demonstrated by HHD. Recurrence was two times more common when the saphenofemoral junction had originally been left intact. Of all recurrent cases, reflux was demonstrated in the long saphenous vein (LSV) above the knee in 62%, in the LSV below the knee in 7%, in the short saphenous vein (SSV) in 16%, in the posterior arch vein in 38%, and in a thigh perforator in 8%. Of the legs reoperated during the follow-up period 41% presented with venous reflux at the follow-up visit. We conclude that HHD efficiently reveals sites of reflux that have been missed during previous surgery and that a thorough preoperative HHD examination and marking of reflux routes is required.