To compare foam sclerotherapy through the access sheath (transluminal foam sclerotherapy [TLFS]) combined with endovenous laser ablation (EVLA) with EVLA alone in terms of safety and one-year venous clinical severity score (VCSS) changes in patients with small saphenous vein incompetence. During EVLA, the sheath tip was placed around the targeted tributary vein, and the sclerosant was injected via the side port. Outcomes assessed at 1day, 1week, 1month, and 1year included VCSS changes, residual or recurrent reflux, the need for secondary interventions, and other related complications. The change in VCSS did not reach the minimum clinically important difference. Otherwise, TLFS reduced residual or recurrent reflux of the tributary using the TLFS (3/74 legs) compared with the EVLA alone (12/77 legs) (p = .027). TLFS is a safe and feasible procedure that reduces residual or recurrent reflux of the tributary vein compared with truncal EVLA alone.