Abstract: The European Society for Clinical Nutrition and Metabolism (ESPEN) online released the latest practical guideline on clinical nutrition in cancer on 15th March, 2021. The new practical guideline is shortened from the ESPEN guideline on nutrition in cancer patients in 2017 for easier use in clinical practice and provides 43 recommendations (without changes compared with the previous guidelines), combined with the diagnosis and treatment flow diagram, on general principles of nutritional therapy for cancer patients and individualized nutritional therapy strategies. Therefore, this new practical guideline is a practical tool for all professionals including physicians, dieticians, nutritionists and nurses in clinical practices.