Aim: Knee osteoarthritis is a degenerative disease complicated by pain and functional limitation. Newer pain-relieving interventions include pulsed radiofrequency (PRF), but studies on its efficacy have limitations including lack of control group and retrospective design that prevent sound conclusions. Materials & methods: We conducted a blind prospective randomized sham-controlled crossover pilot trial according to the CONSORT guidelines, to evaluate the efficacy of ultrasound-guided saphenous nerve PRF in gonarthritis pain. Results: Sixteen patients completed the study. Pain and function significantly improved after real PRF (numerical rating scale mean difference = 3.31), which was superior to sham PRF over time for pain (3 months) and function (6 months). Conclusion: PRF of the saphenous nerve is an alternative to relieve pain in gonarthritis. Our results provide data to support a sample size calculation for future trials. Clinical trial registration: NCT04454710