OBJECTIVE: To verify the effectiveness of a blended-learning voice assistance program for elementary school teachers. STUDY DESIGN: Nonrandomized and comparative interventional clinical trial. METHODS: A total of 59 teachers participated; 33 of the 59 teachers participated in face-to-face learning (control group-CG), and 26 of the 59 teachers participated in blended learning (experimental group-EG). The Voice Assistance Program included the following for both groups: preintervention assessment, four voice workshops and postintervention assessment. The instruments used were the Vocal Production Condition - Teacher (VPC-T) questionnaire, the Screening Index for Voice Disorder (SIVD), the Vocal Health and Hygiene Questionnaire (VHHQ) and the Voice-Related Quality of Life (V-RQOL) measure. Additionally, voice samples were collected for auditory-perceptual analysis of voice quality. The workshops included theoretical and practical content for both groups. All the workshops for the CG were conducted face-to-face, while the workshops for the EG consisted of two online workshops and two face-to-face workshops. A descriptive analysis of the data was performed, and paired Wilcoxon and Mann-Whitney tests were performed using R software, with a significance level of 0.05. RESULTS: Both groups showed improved acquisition of knowledge regarding vocal health and improved voice quality, but the improvement was greater for the EG. There was a significant decrease in the risk of voice disorder in the EG. Only the CG showed significant improvement in voice-related quality of life. CONCLUSION: The voice assistance program with blended learning is effective for increasing knowledge about vocal health, reducing the risk of voice disorder and improving the voice quality of teachers.