Background: Sciatic nerve block is used for orthopedic procedure involving the lower limb.  Parasacral approach for sciatic nerve block may be associated with complications, so single injection popliteal approach with insertion of the needle at the level of separation of tibial and common peroneal nerves was used. Objective: The aim of the current study was to compare between single injection parasacral and popliteal block at neural bifurcation to block the sciatic nerve during below-knee surgeries using combined ultrasound-nerve stimulation as regards the beginning of a total sensory and motor block, the duration of the block and patient satisfaction. Patients and methods: A randomized controlled clinical trial work was conducted at Zagazig University Hospitals on 100 patients of both sexes scheduled to undergo elective below knee surgery. Patients were divided randomly into two groups; Group I: Patients got a single injection to block the parasacral sciatic nerve while being guided by both nerve stimulation and ultrasonography and Group II: Individuals receiving popliteal sciatic block had a single injection in the common epineural sheath under guiding using both ultrasound and nerve stimulation. Patients were followed up for outcomes of usage of each of the blocking techniques. Results: Performance time in popliteal sciatic block approach was significantly shorter than parasacral approach. Also the beginning of a popliteal sciatic block's complete sensory and motor block approaches was considerably shorter than parasacral approach. Conclusion: Combined ultrasound nerve stimulation during below-knee procedures, sciatic nerve block using parasacral and popliteal techniques proved a successful anesthetic strategy. The popliteal sciatic nerve block method, however, is superior to parasacral sciatic nerve blocking in terms of faster block performance and rapid complete sensory and motor block onset.