Results: Pollen dispersal in Osaka Prefecture in 2021 was slightly higher than that in a normal year. Symptom scores, QOL scores, and nasal symptom drug scores were lower in the sublingual immunotherapy group compared to those in the drug treatment group during the 2021 cedar pollen dispersal period. Nasal symptom drug scores in patients who started cedar sublingual immunotherapy in 2018 and 2019 were significantly lower than those in the drug treatment group. Nasal symptom scores did not differ significantly, but there were significant decreases in Face scale scores in the 2018 and 2019 start groups and for the VAS in the 2018, 2019, and 2020 start groups, compared to the drug treatment group.