The invention relates to perhexiline, or a pharmaceutically acceptable salt thereof, for use in the treatment of HfπEF, as well as to a method of treating HfnEF, which comprises administering to an animal in need thereof an effective amount of perhexiline, or a pharmaceutically acceptable salt thereof, to treat said HFnEF. The invention further relates to a treatment programme for treating HFnEF, which involves the co-use or co-administration of perhexiline with one or more other compounds that are advantageous in treating HFnEF or the symptoms thereof.