To explore primary care professionals' perceptions of physical activity and other cancer rehabilitation practice in cancer survivors, investigating the preparedness to implement guidelines regarding cancer rehabilitation. We collected qualitative data through seven semi-structured focus group interviews with 48 rehabilitation professionals, with mean 9 years of experience in primary care rehabilitation (32 physiotherapists, 15 occupational therapists, and 1 rehabilitation assistant) in a primary care setting. Data was analyzed using content analysis. Primary care rehabilitation professionals expressed limited experience of cancer survivors, experienced lack of knowledge of cancer-related disability, and had doubts concerning how to treat cancer survivors. They also experienced uncertainty about where to find collaboration and support in the healthcare system outside their own rehabilitation clinic. There is a need to combine different implementation strategies to tackle multiple barriers for effective cancer survivor rehabilitation in primary care, to boost individual rehabilitation professionals' knowledge and self-efficacy, to clarify roles and responsibilities for cancer rehabilitation across levels of care, and to develop and strengthen organizational bridges to provide adequate access to rehabilitation for cancer survivors.