Background: Patients with head and neck cancer undergoing surgery have a high incidence of ambulatory postoperative complications. Objective: The aim of our study was to investigate the influence of an oral immunoenhanced supplement (arginine and glutamine) on nutritional and biochemical parameters in postsurgical ambulatory patients with head and neck tumor. Design: A population of 39 ambulatory postsurgical patients with oral and laryngeal cancer was enrolled. At Hospital discharge postsurgical head and neck cancer patients were asked to consume two units per day of a specially designed enhanced supplement for a twelve week period. Results: The mean age was 60.2+/-13.1 years (9 female/30 males). Duration of supplementation was 90.8+20 days. A significant increase of albumin (3.1±0.6 g/dl vs 4.12+0.7g /dl;p<0.05), prealbumin (21.4±6.3 mg/dl vs 22.4+5.9 mg/dl;p<0.05) and transferrin (198.8±45.2 mg/dl vs 253.8+60.7 mg/dl; p<0.05) levels were observed. No differences were detected in weight and other anthropometric parameters. Ten patients (41.3%) received radiotherapy along the enhanced supplementation period and only 5 (20% of patients with radiotherapy) developed a clinical oral mucositis. Conclusions: At dose used, arginine and glutamine enhanced formula improved seric protein levels in ambulatory postoperative head and neck cancer patients with a low rate of oral mucositis in the subgroup with radiotherapy.