This report analyses the results obtained using endoscopic cytodiagnosis in upper gastrointestinal lesions. Cytological and bioptic samples were taken from 435 lesions, in 435 patients. Specificity was 0.99% and sensitivity 0.9%. The accuracy of the endoscopic sampling and in preparing the cytological slides had a decisive influence on the obtaining of these results. The time required for a good cytological sample is the same as required for a biopsy. As employed the cytodiagnosis of esophago-gastric lesions was really useful, and indeed essential in diffuse mucosal lesions.