The reported overall prevalence of malnutrition in the oncology population is high at 31%. Consequences of malnutrition include reduced performance status, quality of life, and tolerance to treatment.The aims of this study were to identify and understand oncology clinicians’ knowledge, attitudes, practices and perceived learning needs related to cancer malnutrition. A survey was distributed via Survey Monkey to clinicians working in oncology (medical, nursing, allied health and general practice) through discipline-specific interest groups, professional associations and Integrated Cancer Services. A total of 325 clinicians across all disciplines completed the survey with balanced distribution. Approximately 60% had greater than 5years experience in oncology and almost 80% of participants were from metropolitan regions. The results indicated that participants had inconsistent knowledge regarding the prevalence of cancer malnutrition, criteria for diagnosis and validated screening and assessment tools available. Almost 40% of clinicians self-rated their knowledge as lacking/very poor. The survey highlighted that whilst the majority of clinicians felt patients should be screened for malnutrition throughout their journey, there is variation as to who is believed responsible. A number of clinicians perform nutritional assessment and monitoring, however this is inconsistent and many utilised non-validated measures or tools, potentially giving rise to inappropriate referrals or management. There is inconsistent knowledge, practice and opinion related to cancer malnutrition screening, assessment and management among clinicians. Consequently, oncology patients may not be receiving optimal nutrition care, potentially impeding their health outcomes. Multidisciplinary cancer clinician education is required to ensure appropriate and consistent knowledge and practice.