Background Eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) is a refractory subtype of chronic rhinosinusitis with nasal polyps (CRSwNP), with clinical characteristics differing from those of non-ECRSwNP. We aimed to explore the predictive value of clinical characteristics, including medical history, symptoms, and signs, prior to ECRSwNP diagnosis, and to develop a nomogram for use in clinical practice. Methods A total of 502 patients with CRSwNP were enrolled. Based on the degree of eosinophilic infiltration in nasal polyps (NPs), patients were classified as ECRSwNP or non-ECRSwNP group. Participants' demographic characteristics, asthma history, severity of nasal symptoms (nasal obstruction, rhinorrhea, hyposmia, and facial pain/headache) according to the visual analog scale, and nasal polyp scores based on polyp scoring system were recorded. Logistic regression analysis was performed to screen for independent risk factors, and a model nomogram was constructed. Results The percentage of asthmatic patients and the hyposmia, rhinorrhea, and total nasal symptom scores were significantly higher in ECRSwNP patients than that in non-ECRSwNP patients. The nasal polyp score was lower in the eosinophilic group than that in the non-eosinophilic group. Logistic regression analysis revealed that asthma history and hyposmia, rhinorrhea and nasal polyp scores were independent predictors of ECRSwNP. A nomogram consisting of these four independent risk factors was constructed, and its C-index was 0.808 (95% CI, 0.771 to 0.846). Conclusions The nomogram based on asthma history and olfactory, rhinorrhea, and nasal polyp scores could help predict ECRSwNP, providing a simple, fast, and practical way to distinguish ECRSwNP from non-ECRSwNP cases in clinical practice.