Nilaus Fristrup became an apprentice by tinker Høy and thus got access to G. F. Hetsch's design office and later he was a painter apprentice by the painter and stucco worker Weber. He was educated at The Art Academy from 1852-1864. As a prisoner of war in 1864 he came to Austria, where he also had the opportunity to study art.
After returning home he participated in many important works of decoration like the spectator salon of The Royal Theatre. He became senior teacher at the school of the technical society in 1876. He travelled to Italy more than once, where he gathered inspiration for decorations. In 1883 he became a member of The Art Academy and in 1890 a member of The Academic Counsel.
Nilaus Fristrup was attached to the faience factory Aluminia in 1868 together with Vilhelm Dahlerup and Vilhelm Klein, when Phillip Schou became coowner. This was to improve the artistic quality of the faience.