Objective To investigate the effects of different administration times on the efficacy and safety of subcutaneous immunotherapy using dual mite extracts in patients with allergic rhinitis （AR）. Methods This study was designed as a retrospective cohort analysis. Thirty-nine mite-sensitized AR patients who completed three years of standardized dual-mite subcutaneous immunotherapy （SCIT） were included. Based on self-selected and consistently maintained injection schedules， patients were non-randomly assigned to either a morning dosing group （MD group， 8：00—12：00， n = 19） or an afternoon dosing group （AD group， 14：00—18：00， n = 20）， with further subgroup stratification conducted at 2-hour intervals. Nasal and ocular symptoms were evaluated before and after treatment using the visual analog scale （VAS）， and all adverse reactions were systematically recorded. Results The AD group exhibited significantly greater improvement in nasal itching compared to the MD group （median difference： -2 vs. 0， U = 118.5， P = 0.04， effect size r = 0.33）. The AD group also demonstrated favorable trends toward improved sneezing， nasal congestion， rhinorrhea， and total VAS score， although these differences did not reach statistical significance. In the subgroup analysis by 2-hour intervals， the 16：00—18：00 subgroup showed greater symptom relief than the 8：00—10：00 subgroup， though the difference was not statistically significant. No significant differences were observed between the two groups in the incidence of total， local， or systemic adverse reactions （P > 0.05）， and no moderate or severe systemic adverse events occurred. Conclusions This preliminary retrospective analysis indicates that afternoon administration of dual-mite SCIT， particularly between 16：00 and 18：00， may enhance the improvement of nasal symptoms without elevating safety concerns. The timing of SCIT administration could therefore represent a promising avenue for treatment optimization.