Limited work is available on the benefits of nutritional support enriched with arginine and n-3 fatty acids in surgical patients with head and neck cancer, particularly if well-nourished. We conducted a pilot study in these patients to examine effects on inflammatory markers and clinical outcome. Patients scheduled for radical resection of the oral cavity were randomised to 5 day preoperative and 5 day postoperative Impact® (IMN, n = 4), or no preoperative supplementary nutrition and Isosource® postoperatively (STD, n = 4). Plasma fatty acids, C-reactive protein (CRP), tumour necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10 were measured at baseline, day of surgery and on postoperative days (POD) 2, 4 and 10. Postoperative complications were recorded. The (eicosapentaenoic acid plus docosahexaenoic acid) to arachidonic acid ratio was significantly higher in IMN patients on POD 2, 4 and 10 (P < 0.01). While not statistically significant, CRP, TNF-α, and IL-6 concentrations were higher in the STD group on POD2 while IL-10 was lower. Median length of stay was 10 (range 10-43) days in the IMN group and 21.5 (7-24) days in the STD group. Five complications were seen in the STD group and two in the IMN group. The results support the need for a larger trial focusing on clinical outcome.