Civilization diseases are a growing and global health problem in modern societies. Neurological disorders, cancer, and inflammatory diseases affect a large group of patients around the world. Therefore, it is of utmost importance to search for novel drugs, lifestyle tips, and foods that can help restore balance in the living organism, promote the efficiency of the immune system, and provide satisfactory prophylactic measures. Astragaloside IV (ASIV)—a triterpenoid saponin from Astragalus species, one of the world’s most widely used herbs—has been shown to have a variety of biological properties, including anti-inflammatory, antioxidant, antitumor, and neuroprotective effects. In recent years, the number of in vivo studies on this active ingredient in the scientific literature has increased considerably. The aim of this review was therefore to compile the existing knowledge on the use of this compound in the treatment of selected diseases of civilization—cancer, neurological disorders, and inflammatory diseases—in vivo.