Another early influence was his father's maternal uncle, Johan Conrad Spengler, who in his capacity of inspector of Kunstkammeret was able to give him access to the royal galleries in Christiansborg Palace.

He received instructions in drawing from Martinus Rørbye from 1833 and later also from Christen Købke and Christoffer Wilhelm Eckersberg.

He later continued his training abroad, first in Dresden under Eduard Julius Bendemann (1843–1846) and then in Paris under Thomas Couture (1852–1853).

His daughter Edma Frølich was his favorite model when a baby and a child for his French albums with Pierre-Jules Hetzel.

[7] Carl Nielsen composed the Kantate til Lorenz Frølich-Festen (CNW 103) for Frølich's eightieth birthday, celebrated in Koncertpalæet, Copenhagen, on 30 November 1900.