A 61-year-old male with a 24-year history of unilateral vocal fold paralysis was evaluated by a speech-language pathologist and an otolaryngologist for 52 weeks following Teflon injection. Tape recordings of the patient’s voice were obtained one week prior to and one, eight, 20, and 52 weeks subsequent to Teflon injection. The recorded samples were presented in the backward-play mode to a panel of speech-language pathology graduate students to obtain ratings of the degree of hoarseness, roughness, and pleasantness. Results of the perceptual aspect of this study revealed a general reduction in perceived hoarseness and an enhancement of perceived pleasantness following Teflon injection. Measurement of selected acoustic properties revealed a lowering of median fundamental frequency, a reduction of fundamental aperiodicity for isolated but not excerpted vowels, an elimination of certain frictional noise components, and an increase of certain harmonic components following Teflon injection.