Objectives: Opioid substitution treatment (OST) is often described as a strict and highly regulated treatment method, in which patients have limited influence over their treatment. In 2014, a reform was introduced by the regional council of Skåne in southern Sweden, which allowed OST patients to choose their treatment provider, thus transferring power from care providers to patients. The aim of this study was to examine what this increase in patient influence has meant for the clinics that provide OST in Skåne, and how these clinics have dealt with the new competitive situation that has arisen following the introduction of the reform. Methods: The study is based on two waves of semi-structured interviews with clinic managers at all OST clinics in Skåne. Results: The clinic managers described the increase in patient influence as a positive change, which had led to the patients being treated with more respect. The competition among clinics was expressed, among other things, in the form of differing views on the prescription of benzodiazepines, which initially gave rise to dissatisfaction among clinics with a more restrictive approach to such prescriptions. The reform did not lead to any clear diversity between clinics, apart from different approaches to the prescription of benzodiazepines. The incentive for competition-based diversity is, however, limited by the strict national regulatory system and by the reimbursement system, which restricts the ways in which clinics can conduct treatment activities. Conclusion: OST-clinic managers were largely positive about the increased patient empowerment and the shift in power balance associated with the patient choice reform. The introduction of the reform did not lead to any clear diversity between treatment providers, apart from differing views on the prescription of benzodiazepines, which by some managers was regarded as unfair competition.