Neoplasms of the conjunctiva include many different entities with a broad variety of clinical presentations. This can make a precise clinical diagnosis difficult. R0 resection is the gold standard treatment for most malignant conjunctival neoplasms, but not every benign lesions must treated by excision. In clinical practice it is important to make an accurate clinical diagnosis to enable the best possible management of conjunctival neoplasms.The aim of this study was to determine the accuracy of clinical diagnosis of neoplasms of the conjunctiva.Within a retrospective design, the data from all patients with excision of a conjunctival lesion between 2011 and 2020 in the Department of Ophthalmology of the UKSH Campus Kiel were extracted and analyzed. The specificity, sensitivity, and positive and negative predictive value for the preoperative clinical rating of dignity and diagnosis were evaluated based on the histological diagnostic findings.Of 220 included cases, 75% were benign and 25% malignant. The most frequent neoplasm of the conjunctiva was benign conjunctival nevus. The sensitivity for clinical prediction of a benign lesion was 0.86 (95% confidence interval [CI] 0.59-0.92), the specificity 0.95 (CI 0.85-0.99), and the positive predictive value 0.98 (CI 0.94-1.0). The sensitivity for clinical prediction of malign dignity was 0.95 (CI 0.85-0.99), the specificity 0.88 (CI 0.83-0.93), and the positive predictive value 0.73 (CI 0.61-0.83).The derived values for clinical diagnosis of conjunctival neoplasms can be rated as good. However, in clinical practice, untypical lesions can be hard to diagnose correctly, and the clinical diagnosis should be carefully reviewed; if in doubt, excision should be preferred.