ObjectiveSelf‐efficacy (SE) is an optimistic self‐belief that one can perform a novel task. This concept involves empowerment, self‐esteem, and adaptation to a stressful situation. SE is a strong predictor of health behaviors. Our objectives were to study SE in spasmodic dysphonia (SD) and to develop a disease‐specific SE‐SD scale.Study DesignProspective study.SettingAcademic hospital.Subject and MethodsDisease‐specific SE‐SD items were developed with laryngologists, speech pathologists, and SD patients. These items, General SE Scale, Voice Handicap Index‐10 (VHI‐10), Consensus Auditory Perceptual Evaluation of Voice (CAPE‐V), and Hospital Anxiety and Depression Scale (HADS), were administered to SD patients who presented for botulinum toxin injections.ResultsOne hundred forty‐five SD patients (mean age 59.5 ± 13.6 years) had a general SE score (Cronbach’s α = 0.894) of 33.4 ± 5.2 out of 40. This was negatively correlated with HADS‐A (r = −0.42, P < 0.001) and HADS‐D (r = −0.42, P <. 001), but not correlated with VHI‐10 (r = −0.098, P =. 243) and CAPE‐V (r = −0.047, P =. 57). Factor analysis selected 8 items from the general SE scale and 5 disease‐specific SE‐SD items to generate a 13‐item disease‐specific SE‐SD scale (Cronbach’s α = 0.907). Disease‐specific SE‐SD score was 42.1 ± 6.9 out of 52 and was negatively correlated with VHI‐10 (r = −0.19, P =. 005), HADS‐A (r = −0.43, P <. 001), and HADS‐D (r = −0.57, P <. 001), but not correlated with CAPE‐V (r = −0.024, P =. 60).ConclusionSD patients established on botulinum toxin injections have high degrees of general and disease‐specific SE. Patients with higher SE‐SD demonstrate lower vocal handicap and lower levels of anxiety and depression. A 13‐item disease‐specific SE‐SD scale has been developed.