The purpose of this study was to investigate the effects of the Bel canto singing technique on voice quality in patients with vocal bowing and sulcus vocalis. Five patients with vocal bowing, and five patients with sulcus vocalis participated in the study. Each subject was assessed acoustically (Jitter, Shimmer, NNE) in the first and last session. Dr. Speech (version 4.0, Tiger-DRS) was used to compare acoustic parameters of pre- and post-treatment. The Bel canto singing technique consisted of breathing exercises, relaxation exercises, and phonation exercises. The results showed that the Bel canto singing technique tended to be effective on improving voice quality in patients with organic voice disorders.