A heat-sensitive recording material in which a heat-sensitive recording layer containing a colorless to light-colored basic Leuco dyestuff and a color developer is tightly contacted with a thermal head to effect color development, characterized in that ammonium zirconyl carbonate is contained in said heat-sensitive color-developing layer or in an undercoating layer so as to offer a heat-sensitive recording material which is superior in its high speed printing properties and free from printing hindrances caused by smudge deposition or sticking.
