Objective <p>The aim of this study was to analyse the efficacy of three-dimensional (3D)-printed screw guide-assisted percutaneous metatarsal transverse osteotomy (PMTO) for the treatment of mild-to-moderate hallux valgus (HV).</p> Methods <p>A retrospective case analysis was used to collect the clinical data of 21 patients with mild-to-moderate HV admitted to Shanghai Jiao Tong University School of Medicine Affiliated Sixth People’s Hospital between June 2022 and April 2023, all of whom were treated with 3D-printed screw guide-assisted PMTO, and to compare the pre- and postoperative hallux valgus angle (HVA) and the 1st-2nd intermetatarsal angle (IMA). The duration of surgery and the shortening of the first metatarsal were recorded. The efficacy and function of the patients were assessed via the American Orthopedic Foot and Ankle Surgery Society (AOFAS) forefoot score and visual analogue score (VAS) preoperatively and at the last follow-up. Statistical analysis included normality assessment and internal comparisons (t tests for normally distributed quantitative data and the Mann‒Whitney U test for nonnormally distributed data).</p> Results <p>All patients underwent successful surgery with a mean follow-up of 24.1 ± 2.2&#xa0;months without complications. The mean HVA and IMA were corrected to 11.2 ± 2.6° and 8.1 ± 1.4° from the preoperative values of 32.2 ± 5.0° and 12.6 ± 1.6°, respectively (<i>P</i> &lt; 0.05). The mean shortening of the first metatarsal was 3.2 ± 1.0&#xa0;mm. The average operative duration was 41.0 ± 2.3&#xa0;min. The AOFAS forefoot and VAS scores improved from 59.7 ± 3.6 and 6.1 ± 1.3 preoperatively to 89.8 ± 4.3 and 0.7 ± 0.6 at the last follow-up, respectively (<i>P</i> &lt; 0.05).</p> Conclusion <p>The use of 3D-printed screw guides, improving the safety and effectiveness of PMTO and shortening the operation time, is an effective, efficient and secure way to correct HV deformities.</p> Level of evidence <p>Level IV, retrospective cohort study.</p>