Novel betaine salts of acetylsalicylic acid, namely 4-trimethylammoniobutanoate acetylsalicylate (meldonium acetylsalicylate), Z-carnitine acetylsalicylate and 3- (trimethylammonioamino)-propanoate (meldonium) acetylsalicylate. Use of meldonium acetylsalicylate as antiplatelet agent for treating various pathologies induced by platelet aggregation, anti-inflammatory and antihyperlipidemic agent.