The aim of this study was to document changes from baseline to 6 and 12 months after treatment in health-related quality of life (HRQOL) in relation to sociodemographic and clinical parameters among advanced oral/oropharyngeal cancer patients treated with reconstructive surgery and adjuvant radiotherapy. The HRQOL of 80 consecutive patients was assessed by the EORTC QLQ-C30 and QLQ-H&N35 questionnaires, pretreatment and 6 and 12 months posttreatment. Several patterns of HRQOL changes were distinguished: most general HRQOL issues do not change after treatment or improve compared to baseline scores (emotional functioning, pain, insomnia, constipation) and most head and neck specific issues deteriorate after treatment but return to pretreatment levels at 12 months, except for senses, opening mouth, sticky saliva, and coughing which remain deteriorated in the long term. Although improvement to baseline levels was noted, it should be kept in mind that baseline levels of patients are often deviant from "normal" scores from the general population. Tumour site and stage, comorbidity, and extensive resections were significantly associated with HRQOL outcomes, as were marital status and age. These results, obtained in a homogenous group of patients, may serve as HRQOL benchmarks for future studies investigating surgical and other treatment modalities.