BackgroundAlthough Cotrimoxazole preventive therapy (CPT) has shown to be highly efficacious in reducing morbidity and mortality among people living with Human immunodeficiency virus (HIV) under ‘ideal world’ study conditions, operational challenges are limiting its effectiveness when implementing in countries most affected by the HIV epidemic. The fact that Mozambican authorities reported high coverage of CPT among patients with HIV, has led to this qualitative case study aimed at exploring possible factors responsible for the successful implementation of CPT in the Province of Maputo.MethodsBetween February and April 2019, we individually interviewed nine governmental stakeholders, including the person responsible for the HIV Program, the person responsible for the TB Program and the person responsible for Pharmaceutical management at three administrative levels (central, provincial and district level). Interviews were recorded, transcribed, and analysed thematically using MAXQDA Analytics Pro. Findings were translated from Portuguese into English.ResultsFive themes iteratively emerged: (a) Role of governance & leadership, (b) Pharmaceutical strategies, (c) Service delivery modifications, (d) Health care provider factors, and (e) Patients’ perspectives.Interviews revealed that continuous supply of cotrimoxazole (CTZ) had been facilitated through multiple-source procurement and a push-pull strategy. One part of CTZ arrived in kits that were imported from overseas and distributed to public health facilities based on their number of outpatient consultations (push strategy). Another part of CTZ was locally produced and distributed as per health facility demand (pull strategy). Strong district level accountability also contributed to the public availability of CTZ. Interviewees praised models of differentiated care, the integrated HIV service delivery and drug delivery strategies for reducing long queues at the health facility, better accommodating patients’ needs and reducing their financial and organisational burden.ConclusionsThis study presents aspects that governmental experts believed to be key for the implementation of CPT in the Province of Maputo, Mozambique. Enhancing the implementation outcomes – drug availability and feasibility of the health facility-based service delivery – seemed crucial for the implementation progress. Reasons for the remarkable patient acceptability of CPT in our study setting should be further investigated.