Chronic venous disease (CVD) and hemorrhoidal disease (HD) are among the most common vascular diseases in the world, with CVD affecting 22–41% of the population in Europe and HD having a point prevalence of 11–39%. The burden is substantial in terms of the effect of symptoms on patients’ health-related quality of life (HRQoL) and direct/indirect medical costs. Treatment begins with lifestyle changes, compression in CVD and topical therapies in HD, and escalates as needed through oral therapies first and eventually to surgery for severe disease. CVD and HD share etiological features and pathological changes affecting the structure and function of the tissue extracellular matrix. Mesoglycan, a natural glycosaminoglycan (GAG) preparation composed primarily of heparan sulfate and dermatan sulfate, has been demonstrated to positively impact the underlying causes of CVD and HD, regenerating the glycocalyx and restoring endothelial function, in addition to having antithrombotic, profibrinolytic, anti-inflammatory, antiedema and wound-healing effects. In clinical trials, oral mesoglycan reduced the severity of CVD signs and symptoms, improved HRQoL, and accelerated ulcer healing. In patients with HD, mesoglycan significantly reduced the severity of signs and symptoms and the risk of rectal bleeding. In patients undergoing excisional hemorrhoidectomy, adding mesoglycan to standard postoperative care reduced pain, improved HRQoL, reduced incidence of thrombosis, and facilitated an earlier return to normal activities/work, compared with standard postoperative care alone. The clinical effects of mesoglycan in patients with CVD or HD are consistent with the agent’s known mechanisms of action.