INTRODUCTION: In Indonesia, a country with around 280 million people and the second-highest tuberculosis (TB) incidence rate in the world, the impact of the COVID-19 pandemic on TB care needs careful assessment so that future response strategies can be strengthened. We conducted a study comparing TB testing and treatment rates before and during the first 2 years of the COVID-19 pandemic in Indonesia, and the reasons for any disruptions to care. METHODS: We conducted retrospective secondary data analysis and qualitative interviews in Yogyakarta and Bandung, Indonesia. Routine data on TB testing and treatment were sourced from the national TB information system operated by the Indonesian Ministry of Health. TB testing and treatment outcomes were compared between two time periods: pre-COVID (2018-19); and during COVID-19 (2020-21). In-depth interviews were conducted with patients and health workers to explore their experiences in accessing and providing TB services during the pandemic. RESULTS: There was a 45% (21 937/39 962) reduction in the number of patients tested for TB during the pandemic compared with pre-COVID-19, while the proportion of TB tests returning a positive result increased from 12% (4733/39 962) to 50% (10 945/21 937). The proportion of TB patients completing treatment increased by 2.6% during the pandemic, yet the proportion cured and the number of patients successfully treated both decreased (by 7% and 4.4%, respectively). Our qualitative interviews highlighted several factors influencing TB service access and delivery, including fear of being diagnosed with COVID-19 during TB-related clinic visits, fear of COVID-19 exposure among patients and health workers, healthcare facilities prioritising COVID-19 over other services, and mandatory mobility restrictions affecting both patients and health workers. CONCLUSION: The COVID-19 pandemic impacted TB testing and treatment outcomes in Bandung and Yogyakarta. Policymakers should consider these findings in designing strategies to ensure TB services are maintained and supported during future health crises.