People use their voices in everyday situations and despite all modern technology, voice is still primary and most important medium of communication. Unilateral vocal fold paralysis is associated with changes in perceptual and acoustic voice characteristics and can have a significant impact on patient's quality of life. Objective data regarding the efficacy of voice therapy for unilateral vocal fold paralysis exist. The aim of this study is to determine vocal characteristics in people with unilateral vocal fold paralysis before and after voice therapy. Voice assessment includes perceptual and objective evaluation that is acoustic analysis. This study included 9 female patients aged between 27 and 66. Recordings of conversational speech were used for perceptual evaluation of voice which was assessed by three speech and language therapists experienced in the field of voice pathology. Recorded samples of phonation were analyzed in Praat programme for acoustic analysis of voice. All collected data was processed by descriptive statistics and nonparametric tests. The results of this study show significant difference between perceptual evaluation of voice before and after voice therapy in the form of improved voice quality. According to the perceptual evaluation, voices of all patients was normal or slightly hoarse after therapy. Differences are also found between acoustic analysis before and after voice therapy. For values of shimmer and jitter these differences were statistically significant. The results of the perceptual and objective evaluation, that is acoustic analysis indicate the importance of voice therapy for people with unilateral vocal fold paralysis. It is important to notice that voice therapy is a noninvasive form of rehabilitation and should be the first choice for patients who experience dysphonia as the most severe symptom of unilateral vocal fold paralysis.