Background <p>Postoperative nostril asymmetry remains a challenging issue in aesthetic rhinoplasty. Although nostril retainers are commonly used in cleft-related nasal deformities, their role in aesthetic rhinoplasty has not been well established. This study aimed to evaluate the association between postoperative nostril retainer use and nostril symmetry after aesthetic rhinoplasty.</p> Methods <p>Medical records and standardized basal-view photographs of 128 patients who underwent closed-approach rhinoplasty by a single surgeon in 2022 were retrospectively reviewed. Patients were divided into two groups according to postoperative nostril retainer use. Basal-view photographs obtained at 12 months were evaluated by two independent blinded plastic surgeons using a five-point nostril symmetry rating scale.</p> Results <p>Eighty patients used nostril retainers, and 48 patients did not. The mean nostril symmetry score was significantly higher in the retainer group than in the non-retainer group (4.17 ± 0.56 vs. 3.69 ± 0.71, <i>p</i> = 0.01). Inter-rater agreement was substantial (weighted κ = 0.787, 95% CI 0.691–0.857). No clinically significant retainer-related complications were recorded.</p> Conclusions <p>In this retrospective cohort, postoperative nostril retainer use was associated with higher surgeon-rated nostril symmetry scores at 12 months after aesthetic rhinoplasty. However, because of the retrospective sequential design, self-reported adherence assessment, and subjective photographic outcome measure, these findings should be interpreted as preliminary and hypothesis-generating. Prospective studies using objective three-dimensional measurements and standardized compliance monitoring are warranted.</p> Level of evidence <p>Level III, therapeutic study.</p>