The objective of this research was to evaluate the clinical benefits of using a mini-instrument during endoscopic thyroidectomy via a breast approach (ETBA). Surgery-related indices and cosmetic results were compared for 20 patients underwent ETBA with a mini-instrument (ETBA-m) and 20 patients who underwent standard ETBA (sETBA). Patients were closely matched in terms of age, gender, tumor size, and pathology. Patients who underwent sETBA had a significantly larger area of dissection and total length of incisions compared to patients who underwent ETBA-m (136.25 ± 19.22 cm(2)vs. 105.25 ± 9.54 cm(2), p < 0.001 and 2.66 ± 0.09 cm vs. 2.08 ± 0.24 cm, p < 0.001). All patients who underwent ETBA-m commented that they preferred their current cosmetic appearance after they were shown a picture of the scars of a patient who underwent sETBA. Results of this study revealed that use of a mini-instrument in ETBA is technically safe and feasible and it offers improved cosmetic outcomes compared to sETBA.