Metabolic syndrome (MS) is a modern medical condition characterized by central obesity, hyperglycaemia, hypercholesterolemia and hypertension. The beneficial effects of mushrooms in lowering the symptoms of MS were known from both traditional and conventional medicine. Edible mushrooms, their extracts, polysaccharide fractions and isolated compounds possessed hypoglycaemic, cholesterol and triglyceride lowering ability, hypotensive effects, as well as weight managing activity by influencing satiety. The most active compounds are polysaccharides, called β-glucans, as well as lectines and small compounds such as eritadenin, triterpenes, sterols and phenolic compounds.