Purpose According to the classification of glottic lesions by narrow-band imaging (NBI) proposed by the European Laryngological Society (ELS), lesions without perpendicular patterns are benign, while wide- and narrow-angled perpendicular lesions include both papilloma and carcinoma/high-grade lesions, respectively. The purpose of the study was to investigate the effectiveness of the ELS classification. Methods One hundred and forty four patients with glottic lesions underwent microlaryngoscopy with NBI. The affected vocal cords (arm A) were histologically analysed. The unaffected vocal cords (arm B) were not histologically analysed and were considered to be true negatives if no suspicious changes appeared during the follow-up. The vocal cords from arm A were categorised into three groups—those with a benign disease (papilloma excluded), those with a carcinoma/high-grade lesion and those with papilloma. The ratio of vascular patterns was determined and the groups were statistically compared using the Chi-square test. Results Perpendicular patterns were identified only in 9.3% (9/97) of those in the benign group (without papilloma). Wide-angled patterns were mainly identified in cases of papilloma (80%, 12/15), while the narrow-angled ones were mostly identified in cases of carcinoma and high-grade lesions (96.2%, 76/79) ( P  < 0.001). The sensitivity, specificity, positive and negative predictive values and accuracy were 98%, 95%, 88%, 99% and 95%, respectively. Conclusion The ELS classification of vocal cord lesions by NBI is effective in differentiating between carcinoma/high-grade lesions and papilloma and the remaining benign lesions of the vocal cords.