BACKGROUND: Moderate-to-severe allergic rhinitis (AR) may increase the risk of developing or worsening asthma, whereas treatment of AR with subcutaneously or sublingual allergen immunotherapy (SLIT) may slow this progression. METHODS: In a retrospective real-world analysis, prescription fulfilment data were gathered from French retail pharmacies between 1 March 2012 and 31 December 2016. Using linear regression analyses, patients having received at least two prescriptions of grass pollen SLIT tablets over at least 2 successive years were compared with control patients having received symptomatic medications only. RESULTS: A total of 1099 SLIT patients and 27 475 control patients were included in the main analysis. With regard to symptomatic AR medication dispensing, we observed a 50% decrease in the pre-index/follow-up ratio in the SLIT group, a 30% increase in the control group without age matching (P < 0.0001 vs SLIT) and a 20% increase in the control group with age matching (P < 0.0001 vs SLIT). During the follow-up, 11 (1.8%) and 782 (5.3%) patients initiated asthma treatment in the SLIT and control groups, respectively. The relative risk of medication dispensing for new asthma was lower in the SLIT group (by 62.5% [29.1%-80.1%] without age matching (P = 0.0025) and by 63.7% [31.5%-80.7%] with age matching; P = 0.0018). SLIT was also associated with slower progression of asthma medication dispensing during the follow-up period, relative to the control group (regression coefficient: -0.58 [-0.74 to 0.42] without age matching (P < 0.0001) and -0.61 [-0.76 to -0.46] with age matching; P < 0.0001). CONCLUSION: Prescription of grass pollen SLIT tablets reduced the dispensing of AR and asthma medications in real life.< Réduire