He introduced his nephew to his colleagues, Paul Troger and Franz Anton Maulbertsch and he was an assistant in the latter's workshop from 1763 to 1768.
[1] His first mature work in his own style is an apotheosis of Saint Clement at the parish church in Horní Břečkov, completed in c. 1770.
After marrying and settling in Znojmo, he worked prolifically throughout the area until the early 1780s, when Emperor Joseph II suppressed the monasteries and ordered a reduction in the ornamentation of churches; part of a general program of religious modernization.
These actions had a serious effect on Winterhalder's livelihood, but he was able to find patronage from the Moravian nobility, decorating several of their mansions with trompe-l'œil ornaments and the like.
He also listed his own works in the order of their importance (rating those from the period of suppression at the bottom), and mused about the course of his life.