This study aimed to evaluate the diagnostic value of image-enhanced endoscopy (IEE) in detecting sinonasal inverted papilloma (SNIP). Overall, 86 patients with unilateral nasal papillary or lobulated neoplasms were included between July 2018 and June 2019. All patients underwent IEE examinations, and the diagnosis of all neoplasms was confirmed through postoperative pathology. Logistic regression analysis was conducted to screen for independent predictors of various types of vascular patterns of SNIP. Furthermore, a prognostic nomogram was constructed using the independent predictors screened by logistic regression analysis to evaluate its usefulness in distinguishing SNIP from nasal polyp (NP) and papillary mucosa folds (PMF). In total, 86 consecutive cases were observed, including 37 with SNIP, 40 with NP, and 9 with PMF. Logistic regression analysis showed that spot, corkscrew, and multilayered vascular patterns were independent predictors of SNIP diagnosis. Furthermore, a nomogram comprising the three independent risk factors was constructed with scores of 5, 2, and 3. The area under the receiver operating characteristic curve for predicting SNIP was 0.954, 0.66, 0.71, and 0.76 for the nomogram model, spot vascular pattern, corkscrew vascular pattern, and multilayered vascular pattern, respectively. The nomogram model based on spot, corkscrew, and multilayered vascular patterns in SNIP observed using IEE can be a useful diagnostic tool for predicting and distinguishing between NP and PMF.