Achieving planned sagittal alignment remains a major challenge in adult spinal deformity surgery (ASD),particularly in cases requiring pelvic fixation, where pelvic compensation and rod contouring accuracy influence outcomes. Advances in AI-assisted preoperative planning software allow surgeons to quantitatively visualize and execute individualized correction strategies with patient-specific rods. We report our early clinical experience focusing on the reproducibility of sagittal alignment correction in ASD cases treated with pelvic fixation using this technology. A retrospective review of nine patients with ASD (mean age 66.8 years; four females) who underwent posterior lumbar interbody fusion at L5/S combined with sacral alar–iliac screw fixation between June and December 2025. For all cases, preoperative planning was done using AI-assisted software, and patient-specific rods were industrially manufactured to reproduce the planned sagittal alignment and surgery was performed as planned. Spinopelvic alignment parameters (pelvic incidence, pelvic tilt, sacral slope, thoracic kyphosis, lumbar lordosis, pelvic incidence minus lumbar lordosis mismatch, sagittal vertical axis, pelvic angles, and global tilt) were evaluated using standing whole-spine radiographs obtained preoperatively and at one month postop. Statistical analysis was done using the Wilcoxon matched-pairs test with Bonferroni correction. LL improved from −17.8° preoperatively to −47.9° in the planned alignment and −44.2° postoperatively. PI-LL mismatch improved from 28.8°preoperatively to −1.2°in the plan and 3.3° postoperatively. SVA improved from 85.7mm preoperatively to 16.6mm in the plan and 1.3mm postoperatively. No significant differences were observed between planned and postoperative values for these key parameters. Global sagittal alignment parameters were closely approximated the planned values, demonstrating high correction reproducibility. AI–assisted preoperative planning combined with patient-specific rods enabled highly reproducible sagittal realignment in ASD surgery with pelvic fixation. By minimizing variability related to intraoperative rod bending, correction accuracy was enhanced, particularly in the lumbopelvic region. Despite limitations related to short-term follow-up and small sample size, these findings highlight the educational and clinical value of AI–guided, patient-specific strategies in complex deformity surgery.