To address current trends in poor health-seeking behaviour and late cancer diagnosis in many low- and middle-income countries, like Uganda, it is important to explore innovative awareness building interventions. One possible intervention is a common digital format, an interactive voice response (IVR) system, which is suitable for individuals with low technological and reading literacy. It is increasingly acknowledged that developing digital interventions requires co-creation with relevant stakeholders and explication of program developers’ assumptions, to make them effective, sustainable, and scalable. To this end, we sought to develop an initial program theory for a co-created IVR system for cancer awareness in Uganda. Utilising principles of the realist approach, a qualitative exploratory study was conducted through seven focus group discussions (FGDs) with people living with cancer (PLWC), health workers, and policy makers. Thematic analysis of the transcripts resulted in the emergence of four major themes. Through all themes the most consistent finding was that myths, misconceptions, and misinformation about cancer were related to every aspect of the cancer journey and influenced the experiences and lives of PLWC and their caregivers. Participants were positive about the potential of an IVR system but also had reservations about the design and reach of the system. The resulting initial program theory proposes that a context-specific IVR system has the potential to improve awareness on cancer, provided attention is given to aspects such as language, message framing, and accuracy.