Orbital venous malformation (OVM) is one of the most common orbital mass of adults, accounting for approximately 5% to 15% of all vascular abnormalities in the central nervous system and representing 9% of orbital lesions. Clinical presentation is variable from asymptomatic cases to symptomatic ones. The purpose of the authors' work is to analyze OVM incidence and prevalence in a cohort of patients referred over the last 40 years to the Orbital Unit, tertiary center for orbital diseases.Records of 224 patients diagnosed with CVM in a 40-year period were retrospectively reviewed extracting prevalence/year and incidence/year based on data obtained from Eurostat population statistics. Data were aggregate and analyzed with a Microsoft Excel (Microsoft Corporation, Redmond, WA) spread sheet.The incidence rate was measured as the number of new cases of OVM observed in Orbital Unit, a tertiary center. Incidence was about 1 case out (0.94) every 10 million people. The incidence rate was measured also as the number of new cases of OVM observed in Campania, considering in the latter case patients residents in this region (112 patients). Incidence was less than 1 case out (0.58) every 10 million people.The prevalence rate was measured as the proportion of individuals with OVM observed in our Orbital Unit and is equal to 5%. This indicator resulted to increase from 1977 to 2017.The management of OVM is still under discussion, but in agreement with data present in the literature the authors still believe that the surgical indication is only for symptomatic lesions.