He studied medicine at Freiburg and Vienna, and afterwards, worked as a general practitioner in Freiburg-in-Brisgau.
From 1845 he taught classes in zoology and mineralogy, and in 1854 was named an associate professor of mineralogy and geology at the University of Freiburg, where in 1859 he attained a full professorship.
After much research in geology, he devoted himself to the study of prehistoric people and studied stone tools from an evolutionary point of view and also their geographical distribution.
With Alexander Ecker, he was co-director of the Museum für Urgeschichte und Ethnographie (Museum of Prehistory and Ethnography) at Freiburg.
[2][3] Fischer was elected a member of the American Antiquarian Society in 1881.