The goal of treatment for patients with sinusitis is the prompt and complete relief of symptoms and consequent improvement in health-related quality of life (HRQL). HRQL has been defined as the component of overall quality of life, determined primarily by the person's health, which can be influenced by clinical interventions. HRQL is especially useful for conditions like sinusitis in which there is no gold-standard diagnostic test, and "objective" tests correlate poorly with disease severity and outcomes. Patients with sinusitis have measurable, significant decrements in HRQL. Many studies evaluating treatment efficacy in patients with sinusitis have used unvalidated HRQL measures, making their findings, at best, difficult to interpret or, at worst, potentially biased. In this article, we review the definition of HRQL, the meaning and importance of validating HRQL measures, the impact of sinusitis on HRQL, and validated measures of HRQL for use in research and in clinical practice.