Rembrandt and Caravaggio were primary influences on Nerdrum's work, while secondary influences include Masaccio, Leonardo da Vinci, Michelangelo, Titian and the less obvious influences, according to Vine and either mentioned by Nerdrum himself or other critics, that include Brueghel, Goya, Chardin, Millet, as well the even less apparent Henry Fuseli, Caspar David Friedrich, Ferdinand Hodler, Edvard Munch, Käthe Kollwitz, Salvador Dalí, Chaim Soutine and Lars Hertervig.
Nerdrum creates six to eight paintings per year. These include Still life paintings of small everyday objects like bricks, portraits and self portraits whose subjects are dressed as if from some other time and place, and large paintings, allegorical in nature that present a sense of the apocalyptic and again reference another time. Nerdrum says that his art should be understood as kitsch rather than art as such. "On Kitsch", a manifesto composed by Nerdrum describes the distinction he makes between kitsch and art. Nerdrum's philosophy has spawned The Kitsch Movement among his students and followers, who call themselves kitsch painters as opposed to artists.