The reptile fauna of the Świętokrzyski National Park consists of 6 species: sand lizard, viviparous lizard, also known as common lizard, grass snake, smooth snake, and common European adder, also known as comon Eropean viper.

As far as snake species are concerned, the grass snake is not numerous, and the smooth one is considered to be an endangered species. The common European adder, the only venomous reptile in Poland, can be found more frequently. In the Park, it occurs in all three of its colour-varieties: brown, grey, and black.