INTRODUCTION: Leukoplakia of the vocal cord is the clinical expression of a tissue alteration with variable anatomopathological (AP) characteristics. As it may represent a pre-malignant lesion, identification of dysplastic alterations is very important. Study of the AP profile of leukoplakia is important for establishing protocols and treatments for cancer of the larynx. AIM: To identify the main alterations found in biopsies of vocal cord leukoplakias. METHODS: This prospective observational study involved patients selected after videolaryngoscopy between 05/2008 and 05/2013. Inclusion criteria: Adults with a diagnosis of vocal cord leukoplakia. Exclusion criteria: Previous diagnosis of cancer of the larynx or any other vocal cord lesions. The patients underwent an excisional biopsy and their samples were analyzed. RESULTS: Of the 46 patients assessed, 16 (34.7%) had no dysplasia, 4 (8.6%) had mild dysplasia, 13 (28.2%) had moderate dysplasia, 10 (21.7%) had severe dysplasia/carcinoma in situ, and 3 (6.5%) had invasive carcinoma. CONCLUSION: The most common biopsy findings were mild and moderate dysplasia. A minority of patients presented with no dysplasia. The variability of the biopsy findings and the inability to distinguish benign from malignant lesions based on appearance alone indicate that treatments have to be customized for individual patients. Those with no risk factors may be followed-up with a posterior biopsy if there is no regression. Patients with risk factors should undergo a biopsy soon after diagnosis. This will allow for a faster diagnosis of cancer of the larynx and therefore better treatment options and outcomes.