Postoperative pain within the first 24 h after head and neck cancer (HNC) surgery was assessed. Factors influencing postoperative pain were identified. In a prospective cohort single center study 145 HNC patients rated their pain on the first postoperative day using questionnaires of the German-wide project Quality Improvement in Postoperative Pain Treatment (QUIPS) including numeric rating scales (NRS, 0-10) for the determination of patient's pain on ambulation, his maximal and minimal pain. QUIPS allowed a standardized assessment of patients' characteristics and pain-related parameters. The influence of these parameters on the patients' postoperative pain was estimated by univariate and multivariate statistical analysis. One-third had already pain prior to the surgical intervention. Overall, the mean pain on ambulation, maximal pain and minimal pain were 2.55 ± 2.36, 3.18 ± 2.86, and 1.38 ± 2.86 (NRS), respectively. 53 % of the patients had maximal pain scores >3. Multivariate analysis revealed independent predictors for more postoperative pain on ambulation: intensity of chronic preoperative pain, usage of non-opioids on ward, and existence of pain documentation on ward. Intensity of chronic preoperative pain and usage of non-opioids on ward were independent risk factors for more maximal pain. Intensity of chronic preoperative pain was independently associated to more minimal pain. Concerning pain management side effects, the risk for drowsiness increased with longer time of surgery. Postoperative pain after HNC surgery is highly variable and seems often to be unnecessarily high. Many patients seem to receive less analgesia than needed or ineffective analgesic drug regimes.