Malnutrition is a common problem among patients with head and neck cancer and can have adverse effects on overall health and treatment outcomes. Nutritional and physical prehabilitation are potential strategies to optimize the nutritional status of these patients. This systematic review aimed to identify and describe prehabilitative interventions that can promote an improvement in nutritional status. A systematic review of the literature was conducted in the databases PubMed/Medline, Embase, CINAHL, Scopus and on the platform Web of Science and in Cochrane Library. The selected studies concern adults with head and neck tumours, not malnourished at the time of diagnosis, who undergo nutritional or physical prehabilitation. Out of 1369 results, 7 studies were included. Multimodal prehabilitation interventions that combine nutritional counseling, oral nutritional supplements, and swallowing exercises to prevent dysphagia have shown positive outcomes in maintaining caloric intake, body weight, swallowing ability, and a reduced incidence of fibrosis in the upper gastrointestinal tract, as well as improving quality of life. Despite the limited number of clinical studies available in the literature, the results suggest that nutritional and physical prehabilitation interventions have a positive effect on the nutritional status and clinical outcomes of patients with head and neck cancer, helping mitigate the risk of malnutrition and improve general well-being.