Objective: The adoption of minimally invasive spine surgery techniques has increased globally over the past decade. These techniques are primarily used for percutaneous pedicle screw insertion. Surgeons in low socioeconomic settings often depend on fluoroscopy for accurate placement of percutaneous pedicle screws. Precise medial and sagittal angulation of the Jamshidi needle is essential to prevent misplacement during screw insertion. Here, we present a technique based on trigonometric calculations that allows the accurate determination of the medial angulation of the Jamshidi needle, using intraoperative measurement of the pedicle width at the targeted vertebral body. Methods: All patients who underwent percutaneous pedicle screw insertion using the described method between August 2023 and July 2024 were evaluated by 2 independent observers using computed tomography scan images. Pedicle violations were graded according to the Gertzbin-Robbins scale. The rates of pedicle perforation, significant errors in pedicle cannulation, and postoperative complications were analysed. Interrater reliability and the correlation between intraoperative pedicle width measurements and the medial angulation value of the Jamshidi needle were assessed statistically. Results: The mean age of the patients was 44.5 years. A total of 112 percutaneous pedicle screws were analysed. Among the 15 identified pedicle breaches, 9 were medial and 6 were lateral. The pedicle perforation rate was 13.4%. None of the patients with pedicle breaches developed significant postoperative complications. Interobserver agreement between the 2 evaluators was moderate (kappa coefficient, 0.597; p<0.001). There was a strong and statistically significant positive correlation between pedicle width measurement and the medial angulation value of the Jamshidi needle (r = +0.974, p<0.001). Conclusion The medial angulation of the Jamshidi needle for percutaneous pedicle screw insertion under fluoroscopy can be predicted using intraoperative pedicle width measurements. As the intraoperative pedicle width increases, the medial angulation required for the Jamshidi needle also increases.