RESUMEN
(1) Background: Onychomycosis (OM) is a fungal nail infection, considered a risk factor for diabetic foot ulcers. It is associated with changes in quality of life, in terms of pain, self-confidence and self-esteem. The aim was to translate and adapt the OM quality of life questionnaire "OnyCOE-tTM-Quality Of Life Questionnaire Onychomycosis (Nail Fungal Condition)". (2) Methods: This study followed the guidelines proposed by Beaton et al. (2000), where two English to Portuguese translations were performed and, after an expert consensus, a common version was obtained. This was followed by two back-translations. The expert committee achieved semantic equivalence, idioms and concepts. The pre-test was applied to 49 people. The final version and processed data were sent to the authors. (3) Results: We adapted terms semantically, modified statements syntactically, altering items from interrogative to affirmative. (4) Conclusions: The translated version of the "Quality of life-Onychomycosis" questionnaire suggested that it can be used for further studies to test validity and reliability in this population.