Spemann, who was born at Stuttgart in Germany, worked for a time in his father's bookshop there before graduating in zoology, botany, and physics at the universities of Heidelberg, Munich, and Würzburg. He was first an assistant, then a lecturer, at the Zoological Institute of Würzburg (1894–1908) before becoming professor at Rostock (1909–14). He was then successively associate director of the Kaiser Wilhelm Institute of Biology, Berlin (1914–19), and professor of zoology at Freiburg (1919–35).

Spemann's concept of embryonic induction, based on a lifetime's study of the development of amphibians such as newts, showed that certain parts of the embryo – the organizing centers – direct the development of groups of cells into particular organs and tissues. He further demonstrated an absence of predestined organs or tissues in the earliest stages of embryonic development; tissue excised from one part of the embryo and grafted onto another part will assume the character of the latter, losing its original nature. Spemann's highly original work, for which he received the Nobel Prize in 1935, paved the way for subsequent recognition of similar organizing centers in other animals groups. It is elaborated in Experimentelle Beiträge zu einer Theorie der Entwicklung (1936; Embryonic Development and Induction).