The purpose of this study was to investigate the usefulness of the Dysphonia Severity Index (DST) as an objective multiparametric measurement in assessing dysphonia. The DST was compared with the score on Grade of the GRBAS scale. Investigated was also whether the DST is related to severity of dysphonia, which was represented by different diagnosis groups. Furthermore, it was investigated whether the DST can differentiate between a group of patients and a control group. A total of 294 patients with different voice pathologies were included. A control group consisted of 118 volunteers without any voice complaints. The voices of all participants were perceptually evaluated on Grade, and the DST was measured. The groups of patients with voice complaints have a lower DSI and higher scores on Grade than the control group. The DST was significantly lower when the score on Grade was higher. The DST discriminates between patients with nonorganic voice disorders, vocal fold mass lesions, and vocal fold paresis/paralysis. To determine whether the DST discriminates between patients and controls, the sensitivity and specificity for different DST cutoff points were calculated. With a DST cutoff of 3.0, maximum sensitivity (0.72) and specificity (0.75) were found. We conclude that the DST is a useful instrument to objectively measure the severity of dysphonia.