Type I thyroplasty was performed in 12 patients with unilateral paralysis of the vocal fold. Subjective as well as objective improvement in vocal performance was reported in 11 patients. Aspiration was improved in six out of eight patients. Effort closure was evaluated by the ability of the patient to voluntarily raise his intra-abdominal pressure during Valsalva's manoeuvre. A comparison of pre- and post-thyroplasty measures, showed a statistically significant improvement in the efficacy of effort glottic closure (p < 0.05), indicating a better physical performance. We had one case of wound sepsis and another case of implant extrusion.