Introduction and Aim: The sports industry, with its massive financial flows, has created a platform for opaque economic activities and the black economy phenomenon. This study aimed to analyze the mechanisms, consequences, and regulatory strategies of the black economy in the Iranian sports industry using a qualitative approach.

Methodology: A qualitative approach with grounded theory method (Systematic design of Strauss & Corbin) was employed. Data were collected through in-depth semi-structured interviews with 18 experts knowledgeable about the subject, who were selected using purposive and snowball sampling methods. Data analysis was performed using three-stage coding (open, axial, and selective) in MAXQDA software.

Findings: In the open coding stage, 68 open codes and 18 primary categories were identified. In the axial coding stage, categories were organized within a six-component paradigmatic model (contextual conditions, causal conditions, core phenomenon, intervening conditions, strategies, and consequences). The core phenomenon was identified as "The intertwined black economy and financial corruption in the Iranian sports industry" with instances such as dual contracts, money laundering, and tax evasion. Regulatory strategies were developed at four levels: legal, structural, technological, and supportive-cultural.

Conclusion: The black economy in Iranian sports is a systematic phenomenon with economic (reduced government revenues, financial instability), social (decline in public trust), and organizational (demotivation, institutional weakening) consequences. Financial transparency and the establishment of independent regulatory bodies were identified as the two fundamental pillars in combating this phenomenon.