OBJECTIVES: To develop a new patient-based outcome measure in plastic surgery for head/neck skin lesions for use in audit, clinical trials and effectiveness studies. DESIGN AND SUBJECTS: Questionnaire development and validation study. Qualitative methods, including interviews with 27 patients, were carried out to develop a preliminary version of the questionnaire. The questionnaire was then field tested by postal survey of 141 pre- and 250 post-surgery patients to produce a shortened (item-reduced) questionnaire and to evaluate acceptability, reliability, validity and responsiveness. A second field test was carried out by postal survey in an independent sample of 67 pre-surgery patients to further evaluate the reliability and validity of the questionnaire. MAIN OUTCOME MEASURES: Psychometric properties of acceptability, reliability, validity, and responsiveness were assessed. RESULTS: We developed a new measure, the Patient Outcomes of Surgery-Head/Neck (POS-Head/Neck), which includes a six- and nine-item pre- and post-surgery questionnaire, respectively. Results confirmed the acceptability (missing data <10%, evenly distributed endorsement frequencies), reliability (Cronbach alphas >0.76, item-total correlations >0.22), validity (scale inter-correlations r=0.50, scaling assumptions, correlations with age and sex < -0.25) and responsiveness (effect size=0.63) of the questionnaire. CONCLUSIONS: The POS-Head/Neck is a new surgical outcome measure that can be used to evaluate outcomes in malignant and benign head/neck skin lesions before and after surgery is acceptable to patients and satisfies rigorous scientific criteria.