One of the most important aspects of sublingual immunotherapy (SLIT) is the regimen of administration.To find any differences in symptom-medication scores between the two groups of SLIT tablets and drops, given pre-coseasonally (starting 8 weeks before the pollen season) in children with rhinoconjunctivitis allergy to grass pollen. The secondary outcome were the differences in lung function and induction of T-regulatory forkhead box P3 (FOXP3) positive cells.This was a retrospective, secondary analysis of pooled data obtained from our two prospective randomized placebo controlled trials that involved children who underwent SLIT. Forty-one children, ages 6-18 years, with allergic rhinitis (AR), sensitive to grass pollen, participated in the study.Treatment with both tablets and drops significantly reduced all symptoms (nasal, asthma, and ocular) within the groups; there was no significant difference between both groups. When compared with the tablet therapy, there was a trend for drops therapy to be more effective in the reduction of combined symptom-medication score, but the difference was not statistically significant (p = 0.1036); there was no significant difference in asthma and nasal scores. We showed a significant decrease in the fractional exhaled nitric oxide level comparable in both immunotherapy groups. There were no differences between the groups in the induction of CD4+ CD25+ FOXP3+-positive cells in peripheral blood.Both protocols showed similar decreases in symptom-medication scores; however, when compared with tablet therapy, there was a trend for drops therapy to be more effective in the reduction of combined symptom-medication score.