Aim of the study: The present study aimed to explore the mechanisms of change in emotionally focused couple therapy (EFCT). Method: The research method was applied mixed method, and the analysis method was thematic analysis. The statistical population included couples with troubled relationships and pursuer-withdrawer attachment styles in Isfahan, Iran. Three couples were selected using purposive sampling. To collect data, observation and review of therapy session videos and semi-structured interviews were conducted with the study participants. The validity of the collected data was enhanced using the triangulation method. The data were analyzed using thematic analysis.Findings: The findings included 55 initial codes, 21 sub-themes, and 6 main themes. The main themes were: Establishing Alliance, Understanding the Problem, Gaining Insight, Gaining New Experiences, Practicing, and Gaining Independence. Conclusion: The findings of the present study by extracting the pathways through which EFCT achieves therapeutic changes. Findings provide a ground for more practical mastery of therapy for therapists. Moreover, it supports theorists in further developing the theory. It is suggested that tools for measuring mechanisms of changes in EFCT be prepared and validated.