This study aimed to compare the effectiveness of 2 nutritional assessment tools, the Nutritional Risk Screening Scale 2002 (NRS2002) and the Patient-Generated Subjective Global Assessment (PG-SGA), for evaluating the nutritional status of perioperative head and neck squamous cell carcinoma (HNSCC) patients, to facilitate early nutritional interventions and improve clinical outcomes. An observational, comparative study was conducted at the Zhejiang Cancer Hospital, recruiting patients diagnosed with HNSCC scheduled for surgical treatment. The NRS2002 and PG-SGA were applied to assess patients' nutritional risk at multiple time points: upon admission, the day before surgery, 2 days after surgery, a week after surgery, and at discharge. Statistical analyses were performed using McNemar and Kappa tests to assess differences and consistency between NRS2002 and PG-SGA. A total of 209 patients were included in this study, predominantly male, with an average age of 60 years. Nutritional risk assessments identified an inverted "V" trend in nutritional risk, with the peak occurring 2 days post-surgery. PG-SGA consistently showed a higher screening positivity rate compared to NRS2002. The receiver operating characteristic curve analysis highlighted the discriminative power of both tools, with PG-SGA and NRS2002 showing high area under the curve values. Both NRS2002 and PG-SGA are effective for nutritional screening in HNSCC patients, with PG-SGA demonstrating a slightly higher sensitivity before surgery. PG-SGA may be more suitable for preoperative application, whereas NRS2002 is more appropriate for postoperative use.