Objective: This study aimed to verify the effects of a voice therapy program focusing on patients with muscle tension dysphonia (MTD). Patients and Methods: The sample comprised 30 participants diagnosed with MTD, 8 men and 22 women, none of whom was a voice professional. The assessments and reassessments employed the perceptual-auditory protocol GRBASI, measures of maximum phonation times, s/z ratio, and acoustic voice analysis. The voice therapy program included indirect and direct therapy approaches. Results: All parameters assessed using the GRBASI protocol improved following treatment, particularly in regard to lowering voice strain, which is important when treating MTD. The average overall maximum phonation times increased from 8.15 to 10.8 s, while the average s/z ratio did not significantly change. Among the various acoustic parameters, a positive difference was observed for vocal jitter and shimmer. Conclusions: The therapeutic approach adopted in this study proved effective in the treatment of primary and secondary MTD. Speech therapy favored lower phonation effort, lowered vocal strain, and adequacy of adjustment of laryngeal muscles.