The present study investigates the application of Neuro-Linguistic Programming (NLP) as an innovative approach in second language teaching (SLT) to explore its impact on the professional identity of English as a Foreign Language (EFL) teachers. Employing a sequential explanatory mixed methods design, the research involved 148 Iranian EFL teachers of both genders. The quantitative phase employed NLP and Teacher Professional Identity questionnaires, with a selected group of 20 teachers participating in a four-week NLP training workshop designed to enhance their understanding and application of NLP in classroom discourse. A researcher-designed observation checklist measured teachers' use of NLP techniques. The subsequent qualitative phase involved two rounds of semi-structured interviews with the workshop participants. Spearman rho analysis revealed a significant positive correlation between NLP and the professional identity of EFL instructors. Thematic analysis of qualitative data further affirmed NLP's potential to enhance teaching quality and contribute to teachers' professional identity development. These findings underscore the substantial role of NLP in positively influencing teachers' professional development.