The present study aimed to explore the lived experiences of married Iranian individuals regarding the failure of cognitive-behavioral couple therapy (CBCT). The primary focus was to identify the inhibiting factors that, within Iran's unique socio-cultural context, contribute to therapeutic failure from the clients' perspective. This qualitative research was conducted in 2023–2024 using thematic analysis. A purposive sample of 9 participants was recruited from independent clinics in Tehran, and data were collected through semi-structured interviews until saturation was reached. Data analysis followed the systematic method of Braun and Clarke (2016). The findings revealed that CBCT failure in Iran is the result of a vicious cycle in which the therapist's inability to manage sessions, lack of specialized knowledge, and low self-awareness—which leads to the expression of personal beliefs and cultural biases—merge with weaknesses in specialized couple-therapy competencies, such as ethical violations, disregard for therapeutic structure, excessive homework assignments, and failure to monitor progress. When these therapist-related factors combine with inhibiting couple characteristics, including mandated therapy attendance, responsibility avoidance, and blurred couple boundaries, they produce outcomes such as intensified hopelessness, negative attributions, and premature termination of therapy. These findings underscore the necessity of enhancing therapists' fundamental and specialized competencies, screening for negative prognostic indicators, and intelligently localizing treatment protocols to reduce therapeutic failure.