We conducted a retrospective study of the use of cidofovir and the measles, mumps, and rubella (MMR) vaccineas adjunctive treatments to lesion debridement in patients with recurrent respiratory papillomatosis (RRP).Our study population was made up of 15 children-7 boys and 8 girls, aged 1 to 16 years at diagnosis (mean: 6.2) with pathologically confirmed RRP who had been followed for at least I year. In addition to demographic data, we compiled information on disease severity, the type of adjunctive treatment administered to each patient, the frequency of debridements, the length of observation, and remission rates. Of the 15 patients, 5 had been treated with cidofovirafter debridement (cidofovir-only group), 6 were treated with MMR vaccine after debridement (MMR-only group), 3 were treated with one and later switched to the other based on parental preference, and I received neither treatment, only debridement. The initial mean Derkay disease severity scores were 12.6 for the cidofovir-only group and 11.0 for the MMR-only group (p = 0.61). The cidofovir-only patients underwent an average of 11.8 adjunctive treatments and the MMR-only patients an average of 17.7 (p = 0.33). The average duration of observation was 44.0 months in the cidofovir-only group and 64.7 months in the MMR-only group (p = 0.29). Remission rates were 20% in the cidofovir-only group and 50% in the MMR-only group (p = 0.54). Our study found insufficient evidence of any significant differences between cidofovir and the MMR vaccinein terms of the number and frequency of adjunctive treatments and the rates of remission.