<p>Non-specific low back pain (NSLBP) represents about 80–95% of all LBP cases, yet the optimal lumbar traction position for effective treatment remains debated. To investigate the effect of different positions during lumbar traction on pain, function, and ROM in adults with NSLBP. Thirty participants were randomly allocated to one of three lumbar traction position groups: supine, side-lying, or prone. Outcome measures included the Oswestry Disability Index (ODI), International Physical Activity Questionnaire short form (IPAQ-SF), Finger-to-Floor Test (FFT), and Numerical Pain Rating Scale (NPRS). Measurements were obtained at baseline, after the third session, and after completion of the 3-week intervention. Within-group analysis showed significant improvements in ODI and NPRS scores over time in all three groups (<i>p</i> &lt; 0.001). The supine group demonstrated earlier within-group improvement after the third session (<i>p</i> = 0.012). IPAQ improved significantly only in the side-lying group (<i>p</i> = 0.01), whereas FFT did not show significant changes in any group (<i>p</i> &gt; 0.05). However, between-group analysis revealed no statistically significant differences among the three traction positions at any measurement point for any outcome (<i>p</i> &gt; 0.05). Lumbar traction was associated with improvements in pain and disability regardless of position. However, no traction position demonstrated superiority over the others. The earlier improvement observed in the supine group should be interpreted cautiously because it was based on within-group change rather than between-group superiority. Future studies with larger samples are needed to clarify whether positional differences are clinically meaningful. Also, these findings are limited to male participants and should not be generalized to female populations.</p><p>Trial registration: The trial was registered on 02/02/2025, clinicaltrials.gov, Identifier: (NCT06812338).</p>