Nicolaas Cornelis de Fremery (1770-1844) was one of the early palaeontologists in The Netherlands. After his studies in Leiden he was appointed professor in medicine, pharmacy, chemistry and natural history at the university of Utrecht. De Fremery published in his later years three articles on Dutch fossil mammals. In his first publication on a fossil skull of Bos primigenius, found in 1825 at Eembrugge, he clearly points out his ideas on geology. De Fremery appears to be influenced by the catastrofism theory of Georges Cuvier (1769-1832). De Fremery, however, added some remarkable new views to this widespread theory. The aim of this article is to analyse his work on the palaeozoology and the geology of The Netherlands. Comparisons with some foreign contemporaries are made.