Background: In Mozambique, integrated community case management (iCCM) of diarrhoea, malaria and pneumonia is embedded in the national community health worker (CHW) programme, mainstreaming it into government policy and service delivery. Since its inception in 1978, the CHW programme has functioned unevenly, was suspended in 1989, but relaunched in 2010. To assess the long-term success of iCCM in Mozambique, this article addresses whether the current CHW programme exhibits characteristics that facilitate or impede its sustainability.Methodology: We undertook a qualitative case study based on document review (n = 54) and key informant interviews (n = 21) with respondents from the Ministry of Health (MOH), multilateral and bilateral agencies and non-governmental organizations (NGOs) in Maputo in 2012. Interviews were mostly undertaken in Portuguese and all were coded using NVivo. A sustainability framework guided thematic analysis according to nine domains: strategic planning, organizational capacity, programme adaptation, programme monitoring and evaluation, communications, funding stability, political support, partnerships and public health impact.Results: Government commitment was high, with the MOH leading a consultative process in Maputo and facilitating successful technical coordination. The MOH made strategic decisions to pay CHWs, authorize their prescribing abilities, foster guidance development, support operational planning and incorporate previously excluded ‘old’ CHWs. Nonetheless, policy negotiations excluded certain key actors and uncertainty remains about CHW integration into the civil service and their long-term retention. In addition, reliance on NGOs and donor funding has led to geographic distortions in scaling up, alongside challenges in harmonization. Finally, dependence on external funding, when both external and government funding are declining, may hamper sustainability.Conclusions: Our analysis represents a nuanced assessment of the various domains that influence CHW programme sustainability, highlighting strategic areas such as CHW payment and programme financing. These organizational and contextual determinants of sustainability are central to CHW programme strengthening and iCCM policy support.