Background: The clinical outcomes of open-wedge high-tibial osteotomy (OWHTO) for medial knee osteoarthritis depend mainly on the precision of correction. The present study aimed to determine the efficacy and feasibility of simple navigation technology with an ordinary laser pen and surgical instrument box.Methods: Seventy-one patients were randomly divided into the navigation (n=36) and traditional groups (n=35). In the navigation group, the hip, knee (Fujisawa point), and ankle centers were located preoperatively using the lid of the surgical instrument box. The leg was aligned with an ordinary laser pen. Radiation exposure, operative time and cost, required labor and postoperative complications were evaluated. The visual analog scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were recorded. After 24 months, the femoral tibial angle (FTA), medial proximal tibial angle (MPTA), posterior slope angle (PSA), and rate of excellent correction were recorded. The Kaplan-Meier method was used to evaluate the survival time of affected knees.Results: Radiation exposure, operative time and cost, required labor, rate of excellent correction, and postoperative complications were better in the navigation group than in the traditional group (P < 0.05). Six months postoperatively, the VAS and WOMAC scores were significantly improved in both groups (P < 0.001). At 24 months, the FTA, MPTA and PSA were corrected in both groups (P < 0.001), and no between-group differences were found (P > 0.05). There was no difference in the postoperative knee survival time between the traditional and laser navigation groups (P = 0.533).Conclusions: Simple laser navigation technology can effectively increase the rate of excellent leg alignment correction and reduce radiation exposure, operative time and cost, required labor, and postoperative complications.