Objective <p>To evaluate the psychometric properties of the Spanish version of the Chronic Rhinosinusitis Patient-Reported Outcome (CRS-PRO) measure in patients with chronic rhinosinusitis (CRS), including those with and without nasal polyps.</p> Methods <p>A cross-sectional validation study was conducted with 124 CRS patients recruited from a tertiary otolaryngology center. Internal consistency (Cronbach’s α), test–retest reliability (ICC), construct validity (exploratory factor analysis), concurrent validity (Pearson correlation with NPQ, NOSE-E, and SNOT-22), and discriminative capacity (ROC curve analysis) were assessed. A subsample of 35 patients completed the CRS-PRO twice to evaluate reproducibility.</p> Results <p>Factor analysis confirmed a three-factor structure (rhinologic symptoms, psychosocial impact, and facial discomfort), explaining 69.4% of the variance. Internal consistency was excellent (α = 0.874), and test–retest reliability was very high (ICC = 0.986; SEM = 2; MDC95 = 3). All items demonstrated moderate to high item-total correlations. The CRS-PRO strongly correlated with NPQ (<i>r</i> = 0.848), NOSE-E (<i>r</i> = 0.849), and SNOT-22 (<i>r</i> = 0.803). ROC analysis yielded an AUC of 0.929, with an optimal cut-off point of &gt; 22 points (sensitivity 86.67%, specificity 86.08%) to identify severe symptom burden.</p> Conclusions <p>The Spanish CRS-PRO is a valid, reliable, and efficient instrument for assessing disease-specific quality of life in CRS. Its strong psychometric performance, brevity, and diagnostic accuracy support its use in routine clinical practice, research, and digital health applications. These findings establish the CRS-PRO as a core PROM for Spanish-speaking patients with CRS.</p> Clinical trial registration <p>Not applicable.</p>