Cancer is a leading cause of death for Aboriginal and Torres Strait Islander people, with remoteness increasing the risk for poorer outcomes. Primary health care (PHC) clinics have an important role in cancer screening, diagnosis, and post-discharge cancer care, particularly in remote communities, so accurate, timely communication between hospitals, specialists and PHC clinics is vital. This paper analyses the perspectives of Northern Territory health care professionals on communication between PHC and hospital services related to providing care for Aboriginal people with cancer and recommends strategies for improving communication between services. A qualitative study was undertaken in which semi-structured interviews were conducted with fifty staff from 15 health services (8 regional, remote, and very remote PHC clinics; 3 hospitals; one cancer centre and 3 cancer support services) between 2016 and 2019. Transcripts were thematically analysed, with findings categorized into barriers and enablers to communication. Deficiencies in communication impeded patient care and support. A major barrier was fragmented, inefficient information systems; IT systems across health services were unable to interface, resulting in delayed/missing patient information that impacted discharge and follow up. Other barriers included PHC staff with limited knowledge of cancer, high turnover of PHC staff and tertiary hospital staff with limited understanding of remote health care challenges. Individuals used workarounds to overcome system failures and made substantial efforts around individual patients to improve communication. Specific roles and the use of telehealth between services and centralised cancer care services supported better between-service communication. Communication between hospital services and remote PHC clinics is essential to care for Aboriginal cancer patients; our research identified communication as inadequate in terms of consistency and timeliness. Commitment to more timely communication, health care IT systems that facilitate sharing information, designated staff in PHC clinics to support patients with cancer, dedicated Aboriginal cancer roles and additional resourcing to coordinate telehealth appointments could improve communication and sharing of patient information between services.