Objective: Vietnam, like many low/middle income countries, lacks the infrastructure to provide information and psychosocial support to cancer patients and their carers. We undertook a codesign process to develop a web resource to inform and support carers. Methods: Cancer carers and health care professionals' perspectives regarding information and support needs and the content and delivery of web-based supports, were explored via five focus groups (n = 39) and semistructured interviews (n = 4) in Vietnam in 2018.