OBJECTIVE: The study purpose was to develop an instrument to assess patient comfort and satisfaction with prescribed nasal sprays in the treatment of seasonal allergic rhinitis. METHODS: Standard instrument development methodology was utilized. A list of pertinent items obtained from the literature was formulated. Each Nasal Comfort Index (NCI) draft was scrutinized by experts regarding item appropriateness, wording and anchor labels. Five-point Likert scales were utilized. The NCI was organized into pre-defined categories. Questions were included to establish perceived importance of each category in order to develop weights for determining a total score. Perception of content was assessed by 19 subjects. Qualitative and quantitative data were collected. Item combination/reduction was conducted after pre-test of the instrument. Correlations between domain and total scores were calculated to determine the best of four potential methods for calculating these scores. RESULTS: Literature review revealed no existing validated methods for assessing patient comfort, satisfaction and preferences in the target population. The final selection of items was based on qualitative and quantitative analysis. The resultant NCI contained 20 items which, through factor analysis, resulted in four domains explaining 82% of the variance. The most appropriate scoring method was deemed to be weighted means. CONCLUSIONS: Quantitative analysis confirmed many qualitative findings. A single total score, combining the domain scores, was considered the most clinically relevant method for differentiating the effects of nasal sprays. Validation analysis will occur on data gathered through NCI implementation in a clinical trial.