In one of his works he defended Ulrich von Hutten against Erasmus of Rotterdam and published the manuscripts from the Jan Hus heritage.

After his friend Ulrich von Hutten had died (1523), Brunfels' religious views brought him into a controversy with Martin Luther and Huldrych Zwingli.

Besides of his numerous theological works, Brunfels published treatises on pedagogics, Arabic language, pharmaceutics, entomology[1] and botany.

However, Duane Isely attributes much of Brunfels' popularity to Weiditz, whose woodcuts set a new standard technically, and were done from life, rather being copied from previous works.

Brunfels also introduced information about German plants not found in Dioscorides, and described them independently of their medical values, although the descriptions are often poorly written.