PURPOSE: to analyze and correlate teachers' vocal and articulation parameters in a pre and post vocal improvement program. METHOD: a vocal improvement program was offered to a fundamental education state school, located in Campinas, São Paulo, Brazil. Thirteen teachers agreed to take part in the program, however, due to the exclusion criterion, only five "subjects" were selected for the analysis. Teachers were previously submitted to a laryngologist evaluation. Twelve weekly meetings of one and a half hour each were held in the school. In the first and the last meetings, the teachers made a three sentence-vehicle recording, which were submitted to a perceptual evaluation (pitch, modulation and articulation) and an acoustic analysis (fundamental frequency, the frequency length and two first formants' assessment). Data were submitted to statistic analysis. RESULTS: even with a small number of subjects, the results of this study, suggest significant expansion in the frequency extension and a statistically significant increase of F1 in the post-intervention vowels / i / and / u /. CONCLUSIONS: there were no changes in pitch, modulation and articulation measured through perceptual analysis, and fundamental post-intervention frequency.